diff --git a/neutron/agent/linux/utils.py b/neutron/agent/linux/utils.py
index e186874a720..73ad326bfe2 100644
--- a/neutron/agent/linux/utils.py
+++ b/neutron/agent/linux/utils.py
@@ -164,20 +164,14 @@ def find_child_pids(pid, recursive=False):
     It can also find all children through the hierarchy if recursive=True
     """
     try:
-        raw_pids = execute(['ps', '--ppid', pid, '-o', 'pid='],
-                           log_fail_as_error=False)
-    except exceptions.ProcessExecutionError as e:
-        # Unexpected errors are the responsibility of the caller
-        with excutils.save_and_reraise_exception() as ctxt:
-            # Exception has already been logged by execute
-            no_children_found = e.returncode == 1
-            if no_children_found:
-                ctxt.reraise = False
-                return []
-    child_pids = [x.strip() for x in raw_pids.split('\n') if x.strip()]
+        process = psutil.Process(pid=int(pid))
+    except psutil.NoSuchProcess:
+        return []
+
+    child_pids = [str(p.pid) for p in process.children()]
     if recursive:
         for child in child_pids:
-            child_pids = child_pids + find_child_pids(child, True)
+            child_pids += find_child_pids(child, recursive=True)
     return child_pids
 
 
diff --git a/neutron/tests/functional/agent/linux/test_utils.py b/neutron/tests/functional/agent/linux/test_utils.py
index dde8f225090..b65233efd58 100644
--- a/neutron/tests/functional/agent/linux/test_utils.py
+++ b/neutron/tests/functional/agent/linux/test_utils.py
@@ -141,3 +141,34 @@ class TestGetProcessCountByName(functional_base.BaseSudoTestCase):
         # NOTE(ralonsoh): other tests can spawn sleep processes too, but at
         # this point we know there are, at least, 20 "sleep" processes running.
         self.assertLessEqual(20, number_of_sleep)
+
+
+class TestFindChildPids(functional_base.BaseSudoTestCase):
+
+    def _stop_process(self, process):
+        process.stop(kill_signal=signal.SIGKILL)
+
+    def test_find_child_pids(self):
+        pid = os.getppid()
+        child_pids = utils.find_child_pids(pid)
+        child_pids_recursive = utils.find_child_pids(pid, recursive=True)
+        for _pid in child_pids:
+            self.assertIn(_pid, child_pids_recursive)
+
+        cmd = ['sleep', '100']
+        process = async_process.AsyncProcess(cmd)
+        process.start()
+        common_utils.wait_until_true(lambda: process._process.pid,
+                                     sleep=0.5, timeout=10)
+        self.addCleanup(self._stop_process, process)
+
+        child_pids_after = utils.find_child_pids(pid)
+        child_pids_recursive_after = utils.find_child_pids(pid, recursive=True)
+        self.assertEqual(child_pids, child_pids_after)
+        for _pid in child_pids + [process.pid]:
+            self.assertIn(_pid, child_pids_recursive_after)
+
+    def test_find_non_existing_process(self):
+        with open('/proc/sys/kernel/pid_max', 'r') as fd:
+            pid_max = int(fd.readline().strip())
+        self.assertEqual([], utils.find_child_pids(pid_max))
diff --git a/neutron/tests/unit/agent/linux/test_utils.py b/neutron/tests/unit/agent/linux/test_utils.py
index 8160be95941..308c7f0adad 100644
--- a/neutron/tests/unit/agent/linux/test_utils.py
+++ b/neutron/tests/unit/agent/linux/test_utils.py
@@ -313,37 +313,6 @@ class TestGetCmdlineFromPid(base.BaseTestCase):
         self.assertEqual([], cmdline)
 
 
-class TestFindChildPids(base.BaseTestCase):
-
-    def test_returns_empty_list_for_exit_code_1(self):
-        with mock.patch.object(utils, 'execute',
-                               side_effect=exceptions.ProcessExecutionError(
-                                   '', returncode=1)):
-            self.assertEqual([], utils.find_child_pids(-1))
-
-    def test_returns_empty_list_for_no_output(self):
-        with mock.patch.object(utils, 'execute', return_value=''):
-            self.assertEqual([], utils.find_child_pids(-1))
-
-    def test_returns_list_of_child_process_ids_for_good_ouput(self):
-        with mock.patch.object(utils, 'execute', return_value=' 123 \n 185\n'):
-            self.assertEqual(utils.find_child_pids(-1), ['123', '185'])
-
-    def test_returns_list_of_child_process_ids_recursively(self):
-        with mock.patch.object(utils, 'execute',
-                               side_effect=[' 123 \n 185\n',
-                                            ' 40 \n', '\n',
-                                            '41\n', '\n']):
-            actual = utils.find_child_pids(-1, True)
-            self.assertEqual(actual, ['123', '185', '40', '41'])
-
-    def test_raises_unknown_exception(self):
-        with testtools.ExpectedException(RuntimeError):
-            with mock.patch.object(utils, 'execute',
-                                   side_effect=RuntimeError()):
-                utils.find_child_pids(-1)
-
-
 class TestGetRoothelperChildPid(base.BaseTestCase):
     def _test_get_root_helper_child_pid(self, expected=_marker,
                                         run_as_root=False, pids=None,