diff --git a/src/python/src/grpc/_adapter/fore.py b/src/python/src/grpc/_adapter/fore.py
index 05016cdaf31..69e145e3f61 100644
--- a/src/python/src/grpc/_adapter/fore.py
+++ b/src/python/src/grpc/_adapter/fore.py
@@ -41,7 +41,7 @@ from grpc.framework.base import null
 from grpc.framework.foundation import activated
 from grpc.framework.foundation import logging_pool
 
-_THREAD_POOL_SIZE = 100
+_THREAD_POOL_SIZE = 10
 
 
 @enum.unique
diff --git a/src/python/src/grpc/_adapter/rear.py b/src/python/src/grpc/_adapter/rear.py
index dd0a486117f..b3b0b4ed329 100644
--- a/src/python/src/grpc/_adapter/rear.py
+++ b/src/python/src/grpc/_adapter/rear.py
@@ -41,7 +41,7 @@ from grpc.framework.base import null
 from grpc.framework.foundation import activated
 from grpc.framework.foundation import logging_pool
 
-_THREAD_POOL_SIZE = 100
+_THREAD_POOL_SIZE = 10
 
 _INVOCATION_EVENT_KINDS = (
     _low.Event.Kind.METADATA_ACCEPTED,
diff --git a/src/python/src/grpc/framework/base/implementations_test.py b/src/python/src/grpc/framework/base/implementations_test.py
index 11e49caf756..d40bb4d92ee 100644
--- a/src/python/src/grpc/framework/base/implementations_test.py
+++ b/src/python/src/grpc/framework/base/implementations_test.py
@@ -36,7 +36,7 @@ from grpc.framework.base import interfaces_test_case
 from grpc.framework.base import util
 from grpc.framework.foundation import logging_pool
 
-POOL_MAX_WORKERS = 100
+POOL_MAX_WORKERS = 10
 DEFAULT_TIMEOUT = 30
 MAXIMUM_TIMEOUT = 60
 
diff --git a/src/python/src/grpc/framework/face/_test_case.py b/src/python/src/grpc/framework/face/_test_case.py
index b3a012db001..642d500628d 100644
--- a/src/python/src/grpc/framework/face/_test_case.py
+++ b/src/python/src/grpc/framework/face/_test_case.py
@@ -35,7 +35,7 @@ from grpc.framework.face.testing import test_case
 from grpc.framework.foundation import logging_pool
 
 _TIMEOUT = 3
-_MAXIMUM_POOL_SIZE = 100
+_MAXIMUM_POOL_SIZE = 10
 
 
 class FaceTestCase(test_case.FaceTestCase):
diff --git a/src/python/src/grpc/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py b/src/python/src/grpc/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
index 0d51b64f1b3..21bf9a42486 100644
--- a/src/python/src/grpc/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
+++ b/src/python/src/grpc/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
@@ -44,7 +44,7 @@ from grpc.framework.foundation import future
 from grpc.framework.foundation import logging_pool
 
 _TIMEOUT = 3
-_MAXIMUM_POOL_SIZE = 100
+_MAXIMUM_POOL_SIZE = 10
 
 
 class _PauseableIterator(object):