diff --git a/pkg/reconciler/pipelinerun/pipelinerun_test.go b/pkg/reconciler/pipelinerun/pipelinerun_test.go
index 2cffc61939c..16ca139eb01 100644
--- a/pkg/reconciler/pipelinerun/pipelinerun_test.go
+++ b/pkg/reconciler/pipelinerun/pipelinerun_test.go
@@ -175,13 +175,16 @@ func getTaskRunByName(t *testing.T, taskRuns map[string]*v1beta1.TaskRun, expect
 	return tr
 }
 
-// getTaskRunsForPipelineRun returns the set of TaskRuns associated with the input PipelineRun.
-// It will fatal the test if an error occurred.
-func getTaskRunsForPipelineRun(ctx context.Context, t *testing.T, clients test.Clients, namespace string, prName string) map[string]*v1beta1.TaskRun {
+// getTaskRunsForPipelineRun returns the set of TaskRuns associated with the input PipelineRun and optional
+// input of a PipelineTask Label selector. It will fatal the test if an error occurred.
+func getTaskRunsForPipelineRun(ctx context.Context, t *testing.T, clients test.Clients, namespace string, prName string, ptLabel string) map[string]*v1beta1.TaskRun {
 	t.Helper()
-
+	labelSelector := pipeline.PipelineRunLabelKey + "=" + prName
+	if ptLabel != "" {
+		labelSelector += "," + pipeline.PipelineTaskLabelKey + "=" + ptLabel
+	}
 	opt := metav1.ListOptions{
-		LabelSelector: pipeline.PipelineRunLabelKey + "=" + prName,
+		LabelSelector: labelSelector,
 	}
 
 	taskRuns, err := clients.Pipeline.TektonV1beta1().TaskRuns(namespace).List(ctx, opt)
@@ -330,7 +333,7 @@ spec:
 	}
 	reconciledRun, clients := prt.reconcileRun(namespace, prName, wantEvents, false)
 
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	// Ensure that there are 2 TaskRuns associated with this PipelineRun
 	validateTaskRunsCount(t, taskRuns, 2)
 
@@ -603,7 +606,7 @@ spec:
 	reconciledRun, clients := prt.reconcileRun(namespace, prName, wantEvents, false)
 
 	// Check that the expected TaskRun was created
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	validateTaskRunsCount(t, taskRuns, 1)
 
 	actual := getTaskRunByName(t, taskRuns, trName)
@@ -1151,7 +1154,7 @@ status:
 	}
 	reconciledRun, clients := prt.reconcileRun(namespace, pipelineRunName, wantEvents, false)
 
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, pipelineRunName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, pipelineRunName, "")
 	validateTaskRunsCount(t, taskRuns, 1)
 
 	// This PipelineRun should still be complete and the status should reflect that
@@ -2862,7 +2865,7 @@ spec:
 	_, clients := prt.reconcileRun(namespace, prName, []string{}, false)
 
 	// Check that the expected TaskRun was created
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	validateTaskRunsCount(t, taskRuns, 1)
 
 	actual := getTaskRunByName(t, taskRuns, trName)
@@ -3114,7 +3117,7 @@ spec:
 	_, clients := prt.reconcileRun("foo", prName, []string{}, false)
 
 	// Check that the expected TaskRun was created
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	validateTaskRunsCount(t, taskRuns, 1)
 
 	actual := getTaskRunByName(t, taskRuns, trName)
@@ -5012,7 +5015,7 @@ status:
 	defer prt.Cancel()
 
 	reconciledRun, clients := prt.reconcileRun(namespace, prOutOfSyncName, []string{}, false)
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prOutOfSyncName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prOutOfSyncName, "")
 	validateTaskRunsCount(t, taskRuns, 2)
 
 	// This PipelineRun should still be running and the status should reflect that
@@ -6380,7 +6383,7 @@ metadata:
 	reconciledRun, clients := prt.reconcileRun(namespace, prName, wantEvents, false)
 
 	// Check that the expected TaskRun was created
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	validateTaskRunsCount(t, taskRuns, 1)
 
 	actual := getTaskRunByName(t, taskRuns, trName)
@@ -6459,7 +6462,7 @@ spec:
 	reconciledRun, clients := prt.reconcileRun(namespace, prName, nil, false)
 
 	// Check that the expected TaskRun was created
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	validateTaskRunsCount(t, taskRuns, 1)
 
 	actual := getTaskRunByName(t, taskRuns, trName)
@@ -7357,7 +7360,7 @@ spec:
 
 	_, clients := prt.reconcileRun(namespace, prName, []string{}, false)
 
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	validateTaskRunsCount(t, taskRuns, 1)
 
 	actual := getTaskRunByName(t, taskRuns, trName)
@@ -7434,7 +7437,7 @@ spec:
 
 	_, clients := prt.reconcileRun(namespace, prName, []string{}, false)
 
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	validateTaskRunsCount(t, taskRuns, 1)
 
 	actual := getTaskRunByName(t, taskRuns, trName)
@@ -10358,7 +10361,7 @@ spec:
 	reconciledRun, clients := prt.reconcileRun(namespace, prName, wantEvents, false)
 
 	// Check that the expected TaskRun was created
-	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName)
+	taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, namespace, prName, "")
 	// Ensure that there are 2 TaskRuns associated with this PipelineRun
 	validateTaskRunsCount(t, taskRuns, 2)
 
@@ -10849,3 +10852,344 @@ spec:
 		t.Errorf("Expected PipelineRun to be create run failed, but condition reason is %s", reconciledRun.Status.GetCondition(apis.ConditionSucceeded))
 	}
 }
+
+func TestReconciler_PipelineTaskMatrixResultsWithArrayIndexing(t *testing.T) {
+	names.TestingSeed()
+	task := parse.MustParseV1beta1Task(t, `
+metadata:
+  name: mytask
+  namespace: foo
+spec:
+  params:
+    - name: platform
+      default: mac
+  steps:
+    - name: echo
+      image: alpine
+      script: |
+        echo "$(params.platform)"
+`)
+	taskwithresults := parse.MustParseV1beta1Task(t, `
+metadata:
+  name: taskwithresults
+  namespace: foo
+spec:
+  results:
+    - name: platforms
+      type: array
+  steps:
+    - name: produce-a-list-of-platforms
+      image: bash:latest
+      script: |
+        #!/usr/bin/env bash
+        echo -n "[\"linux\",\"mac\",\"windows\"]" | tee $(results.platforms.path)
+`)
+
+	cms := []*corev1.ConfigMap{withEnabledAlphaAPIFields(newFeatureFlagsConfigMap())}
+	cms = append(cms, withMaxMatrixCombinationsCount(newDefaultsConfigMap(), 10))
+	tests := []struct {
+		name                string
+		pName               string
+		p                   *v1beta1.Pipeline
+		tr                  *v1beta1.TaskRun
+		expectedTaskRuns    []*v1beta1.TaskRun
+		expectedPipelineRun *v1beta1.PipelineRun
+	}{{
+		name:  "indexing results in params",
+		pName: "p-dag",
+		p: parse.MustParseV1beta1Pipeline(t, fmt.Sprintf(`
+metadata:
+  name: %s
+  namespace: foo
+spec:
+  tasks:
+    - name: pt-with-result
+      params:
+       - name: platforms
+         type: array
+      taskRef:
+        name: taskwithresults
+    - name: echo-platforms
+      params:
+        - name: platforms
+          value:
+            - $(tasks.pt-with-result.results.platforms[0])
+            - $(tasks.pt-with-result.results.platforms[1])
+            - $(tasks.pt-with-result.results.platforms[2])
+      taskRef:
+        name: mytask
+`, "p-dag")),
+		tr: mustParseTaskRunWithObjectMeta(t,
+			taskRunObjectMeta("pr-pt-with-result", "foo",
+				"pr", "p-dag", "pt-with-result", false),
+			`
+spec:
+  serviceAccountName: test-sa
+  taskRef:
+    name: taskwithresults
+status:
+ conditions:
+  - type: Succeeded
+    status: "True"
+    reason: Succeeded
+    message: All Tasks have completed executing
+ taskResults:
+  - name: platforms
+    value:
+     - linux
+     - mac
+     - windows
+`),
+		expectedTaskRuns: []*v1beta1.TaskRun{
+			mustParseTaskRunWithObjectMeta(t,
+				taskRunObjectMeta("pr-echo-platforms", "foo",
+					"pr", "p", "echo-platforms", false),
+				`
+spec:
+  params:
+  - name: platforms
+    value:
+      - linux
+      - mac
+      - windows
+  serviceAccountName: test-sa
+  taskRef:
+    name: mytask
+    kind: Task
+`),
+		},
+		expectedPipelineRun: parse.MustParseV1beta1PipelineRun(t, `
+metadata:
+  name: pr
+  namespace: foo
+  annotations: {}
+  labels:
+    tekton.dev/pipeline: p-dag
+spec:
+  serviceAccountName: test-sa
+  pipelineRef:
+    name: p-dag
+status:
+  pipelineSpec:
+    tasks:
+    - name: pt-with-result
+      params:
+        - name: platforms
+          type: array
+      taskRef:
+        name: taskwithresults
+        kind: Task
+    - name: echo-platforms
+      taskRef:
+        name: mytask
+        kind: Task
+      params:
+        - name: platforms
+          value:
+            - $(tasks.pt-with-result.results.platforms[0])
+            - $(tasks.pt-with-result.results.platforms[1])
+            - $(tasks.pt-with-result.results.platforms[2])
+  conditions:
+  - type: Succeeded
+    status: "Unknown"
+    reason: "Running"
+    message: "Tasks Completed: 1 (Failed: 0, Cancelled 0), Incomplete: 1, Skipped: 0"
+  childReferences:
+  - apiVersion: tekton.dev/v1beta1
+    kind: TaskRun
+    name: pr-pt-with-result
+    pipelineTaskName: pt-with-result
+  - apiVersion: tekton.dev/v1beta1
+    kind: TaskRun
+    name: pr-echo-platforms
+    pipelineTaskName: echo-platforms
+`),
+	}, {
+		name:  "indexing results in matrix.params",
+		pName: "p-dag-2",
+		p: parse.MustParseV1beta1Pipeline(t, fmt.Sprintf(`
+metadata:
+  name: %s
+  namespace: foo
+spec:
+  tasks:
+    - name: pt-with-result
+      params:
+       - name: platforms
+         type: array
+      taskRef:
+        name: taskwithresults
+    - name: echo-platforms
+      matrix:
+        params:
+          - name: platform
+            value:
+              - $(tasks.pt-with-result.results.platforms[0])
+              - $(tasks.pt-with-result.results.platforms[1])
+              - $(tasks.pt-with-result.results.platforms[2])
+      taskRef:
+        name: mytask
+`, "p-dag-2")),
+		tr: mustParseTaskRunWithObjectMeta(t,
+			taskRunObjectMeta("pr-pt-with-result", "foo",
+				"pr", "p-dag-2", "pt-with-result", false),
+			`
+spec:
+  serviceAccountName: test-sa
+  taskRef:
+    name: taskwithresults
+status:
+ conditions:
+  - type: Succeeded
+    status: "True"
+    reason: Succeeded
+    message: All Tasks have completed executing
+ taskResults:
+  - name: platforms
+    value:
+     - linux
+     - mac
+     - windows
+`),
+		expectedTaskRuns: []*v1beta1.TaskRun{
+			mustParseTaskRunWithObjectMeta(t,
+				taskRunObjectMeta("pr-echo-platforms-0", "foo",
+					"pr", "p", "echo-platforms", false),
+				`
+spec:
+  params:
+  - name: platform
+    value: linux
+  serviceAccountName: test-sa
+  taskRef:
+    name: mytask
+    kind: Task
+`),
+			mustParseTaskRunWithObjectMeta(t,
+				taskRunObjectMeta("pr-echo-platforms-1", "foo",
+					"pr", "p", "echo-platforms", false),
+				`
+spec:
+  params:
+  - name: platform
+    value: mac
+  serviceAccountName: test-sa
+  taskRef:
+    name: mytask
+    kind: Task
+`),
+			mustParseTaskRunWithObjectMeta(t,
+				taskRunObjectMeta("pr-echo-platforms-2", "foo",
+					"pr", "p", "echo-platforms", false),
+				`
+spec:
+  params:
+  - name: platform
+    value: windows
+  serviceAccountName: test-sa
+  taskRef:
+    name: mytask
+    kind: Task
+`),
+		},
+		expectedPipelineRun: parse.MustParseV1beta1PipelineRun(t, `
+metadata:
+  name: pr
+  namespace: foo
+  annotations: {}
+  labels:
+    tekton.dev/pipeline: p-dag-2
+spec:
+  serviceAccountName: test-sa
+  pipelineRef:
+    name: p-dag-2
+status:
+  pipelineSpec:
+    tasks:
+    - name: pt-with-result
+      params:
+        - name: platforms
+          type: array
+      taskRef:
+        name: taskwithresults
+        kind: Task
+    - name: echo-platforms
+      taskRef:
+        name: mytask
+        kind: Task
+      matrix:
+        params:
+          - name: platform
+            value:
+              - $(tasks.pt-with-result.results.platforms[0])
+              - $(tasks.pt-with-result.results.platforms[1])
+              - $(tasks.pt-with-result.results.platforms[2])
+  conditions:
+  - type: Succeeded
+    status: "Unknown"
+    reason: "Running"
+    message: "Tasks Completed: 1 (Failed: 0, Cancelled 0), Incomplete: 1, Skipped: 0"
+  childReferences:
+  - apiVersion: tekton.dev/v1beta1
+    kind: TaskRun
+    name: pr-pt-with-result
+    pipelineTaskName: pt-with-result
+  - apiVersion: tekton.dev/v1beta1
+    kind: TaskRun
+    name: pr-echo-platforms-0
+    pipelineTaskName: echo-platforms
+  - apiVersion: tekton.dev/v1beta1
+    kind: TaskRun
+    name: pr-echo-platforms-1
+    pipelineTaskName: echo-platforms
+  - apiVersion: tekton.dev/v1beta1
+    kind: TaskRun
+    name: pr-echo-platforms-2
+    pipelineTaskName: echo-platforms
+`),
+	}}
+	for _, tt := range tests {
+		t.Run(tt.pName, func(t *testing.T) {
+			pr := parse.MustParseV1beta1PipelineRun(t, fmt.Sprintf(`
+metadata:
+  name: pr
+  namespace: foo
+spec:
+  serviceAccountName: test-sa
+  pipelineRef:
+    name: %s
+`, tt.pName))
+			d := test.Data{
+				PipelineRuns: []*v1beta1.PipelineRun{pr},
+				Pipelines:    []*v1beta1.Pipeline{tt.p},
+				Tasks:        []*v1beta1.Task{task, taskwithresults},
+				ConfigMaps:   cms,
+			}
+			if tt.tr != nil {
+				d.TaskRuns = []*v1beta1.TaskRun{tt.tr}
+			}
+			prt := newPipelineRunTest(t, d)
+			defer prt.Cancel()
+			_, clients := prt.reconcileRun("foo", "pr", []string{}, false)
+
+			taskRuns := getTaskRunsForPipelineRun(prt.TestAssets.Ctx, t, clients, pr.Namespace, pr.Name, "echo-platforms")
+			validateTaskRunsCount(t, taskRuns, len(tt.expectedTaskRuns))
+			for _, expectedTaskRun := range tt.expectedTaskRuns {
+				trName := expectedTaskRun.Name
+				actual := getTaskRunByName(t, taskRuns, trName)
+				expectedTaskRun.Labels["tekton.dev/pipeline"] = tt.pName
+				expectedTaskRun.Labels["tekton.dev/memberOf"] = "tasks"
+				if d := cmp.Diff(expectedTaskRun, actual, ignoreResourceVersion, ignoreTypeMeta); d != "" {
+					t.Errorf("expected to see TaskRun %v created. Diff %s", expectedTaskRun.Name, diff.PrintWantGot(d))
+				}
+			}
+			pipelineRun, err := clients.Pipeline.TektonV1beta1().PipelineRuns("foo").Get(prt.TestAssets.Ctx, "pr", metav1.GetOptions{})
+			if err != nil {
+				t.Fatalf("Got an error getting reconciled run out of fake client: %s", err)
+			}
+			if d := cmp.Diff(tt.expectedPipelineRun, pipelineRun, ignoreResourceVersion, ignoreTypeMeta, ignoreLastTransitionTime, ignoreStartTime, ignoreFinallyStartTime, cmpopts.EquateEmpty()); d != "" {
+				t.Errorf("expected PipelineRun was not created. Diff %s", diff.PrintWantGot(d))
+			}
+		})
+	}
+}