diff --git a/changelog/632.feature.rst b/changelog/632.feature.rst
new file mode 100644
index 00000000..2c023bcf
--- /dev/null
+++ b/changelog/632.feature.rst
@@ -0,0 +1 @@
+LoadScope scheduler: Sort scopes by number of tests to assign biggest scopes first.
\ No newline at end of file
diff --git a/src/xdist/scheduler/loadscope.py b/src/xdist/scheduler/loadscope.py
index 31dbe26c..59c262d5 100644
--- a/src/xdist/scheduler/loadscope.py
+++ b/src/xdist/scheduler/loadscope.py
@@ -349,11 +349,18 @@ def schedule(self):
             return
 
         # Determine chunks of work (scopes)
+        unsorted_workqueue = OrderedDict()
         for nodeid in self.collection:
             scope = self._split_scope(nodeid)
-            work_unit = self.workqueue.setdefault(scope, default=OrderedDict())
+            work_unit = unsorted_workqueue.setdefault(scope, default=OrderedDict())
             work_unit[nodeid] = False
 
+        # Insert tests scopes into work queue ordered by number of tests
+        for scope, nodeids in sorted(
+            unsorted_workqueue.items(), key=lambda item: -len(item[1])
+        ):
+            self.workqueue[scope] = nodeids
+
         # Avoid having more workers than work
         extra_nodes = len(self.nodes) - len(self.workqueue)