diff --git a/github/repos_properties.go b/github/repos_properties.go
index 5a8626c453..5b12bc8b30 100644
--- a/github/repos_properties.go
+++ b/github/repos_properties.go
@@ -31,3 +31,30 @@ func (s *RepositoriesService) GetAllCustomPropertyValues(ctx context.Context, or
 
 	return customPropertyValues, resp, nil
 }
+
+// CreateOrUpdateCustomProperties creates new or updates existing custom property values for a repository.
+//
+// GitHub API docs: https://docs.github.com/rest/repos/custom-properties#create-or-update-custom-property-values-for-a-repository
+//
+//meta:operation PATCH /repos/{owner}/{repo}/properties/values
+func (s *RepositoriesService) CreateOrUpdateCustomProperties(ctx context.Context, org, repo string, customPropertyValues []*CustomPropertyValue) (*Response, error) {
+	u := fmt.Sprintf("repos/%v/%v/properties/values", org, repo)
+
+	params := struct {
+		Properties []*CustomPropertyValue `json:"properties"`
+	}{
+		Properties: customPropertyValues,
+	}
+
+	req, err := s.client.NewRequest("PATCH", u, params)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := s.client.Do(ctx, req, nil)
+	if err != nil {
+		return resp, err
+	}
+
+	return resp, nil
+}
diff --git a/github/repos_properties_test.go b/github/repos_properties_test.go
index ee231a138c..5ce05c26d7 100644
--- a/github/repos_properties_test.go
+++ b/github/repos_properties_test.go
@@ -63,3 +63,31 @@ func TestRepositoriesService_GetAllCustomPropertyValues(t *testing.T) {
 		return resp, err
 	})
 }
+
+func TestRepositoriesService_CreateOrUpdateCustomProperties(t *testing.T) {
+	client, mux, _, teardown := setup()
+	defer teardown()
+
+	mux.HandleFunc("/repos/usr/r/properties/values", func(w http.ResponseWriter, r *http.Request) {
+		testMethod(t, r, "PATCH")
+		w.WriteHeader(http.StatusNoContent)
+	})
+
+	ctx := context.Background()
+	RepoCustomProperty := []*CustomPropertyValue{
+		{
+			PropertyName: "environment",
+			Value:        String("production"),
+		},
+	}
+	_, err := client.Repositories.CreateOrUpdateCustomProperties(ctx, "usr", "r", RepoCustomProperty)
+	if err != nil {
+		t.Errorf("Repositories.CreateOrUpdateCustomProperties returned error: %v", err)
+	}
+
+	const methodName = "CreateOrUpdateCustomProperties"
+
+	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
+		return client.Repositories.CreateOrUpdateCustomProperties(ctx, "usr", "r", RepoCustomProperty)
+	})
+}