diff --git a/neutron/agent/l3/agent.py b/neutron/agent/l3/agent.py
index 5ef8c7520d6..0805c5d7672 100644
--- a/neutron/agent/l3/agent.py
+++ b/neutron/agent/l3/agent.py
@@ -22,6 +22,7 @@ from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants as lib_const
 from neutron_lib import context as n_context
+from oslo_concurrency import lockutils
 from oslo_config import cfg
 from oslo_context import context as common_context
 from oslo_log import log as logging
@@ -81,6 +82,9 @@ PD_UPDATE = 5
 RELATED_ACTION_MAP = {DELETE_ROUTER: DELETE_RELATED_ROUTER,
                       ADD_UPDATE_ROUTER: ADD_UPDATE_RELATED_ROUTER}
 
+ROUTER_PROCESS_GREENLET_MAX = 32
+ROUTER_PROCESS_GREENLET_MIN = 8
+
 
 def log_verbose_exc(message, router_payload):
     LOG.exception(message)
@@ -255,6 +259,8 @@ class L3NATAgent(ha.AgentMixin,
             self.driver,
             self.metadata_driver)
 
+        # L3 agent router processing green pool
+        self._pool = eventlet.GreenPool(size=ROUTER_PROCESS_GREENLET_MIN)
         self._queue = queue.ResourceProcessingQueue()
         super(L3NATAgent, self).__init__(host=self.conf.host)
 
@@ -372,6 +378,15 @@ class L3NATAgent(ha.AgentMixin,
 
         return legacy_router.LegacyRouter(*args, **kwargs)
 
+    @lockutils.synchronized('resize_greenpool')
+    def _resize_process_pool(self):
+        self._pool_size = max([ROUTER_PROCESS_GREENLET_MIN,
+                               min([ROUTER_PROCESS_GREENLET_MAX,
+                                    len(self.router_info)])])
+        LOG.info("Resizing router processing queue green pool size to: %d",
+                 self._pool_size)
+        self._pool.resize(self._pool_size)
+
     def _router_added(self, router_id, router):
         ri = self._create_router(router_id, router)
         registry.notify(resources.ROUTER, events.BEFORE_CREATE,
@@ -394,6 +409,8 @@ class L3NATAgent(ha.AgentMixin,
                     LOG.exception('Error while deleting router %s',
                                   router_id)
 
+        self._resize_process_pool()
+
     def _safe_router_removed(self, router_id):
         """Try to delete a router and return True if successful."""
 
@@ -437,6 +454,8 @@ class L3NATAgent(ha.AgentMixin,
 
         registry.notify(resources.ROUTER, events.AFTER_DELETE, self, router=ri)
 
+        self._resize_process_pool()
+
     def init_extension_manager(self, connection):
         l3_ext_manager.register_opts(self.conf)
         self.agent_api = l3_ext_api.L3AgentExtensionAPI(self.router_info)
@@ -673,9 +692,8 @@ class L3NATAgent(ha.AgentMixin,
 
     def _process_routers_loop(self):
         LOG.debug("Starting _process_routers_loop")
-        pool = eventlet.GreenPool(size=8)
         while True:
-            pool.spawn_n(self._process_router_update)
+            self._pool.spawn_n(self._process_router_update)
 
     # NOTE(kevinbenton): this is set to 1 second because the actual interval
     # is controlled by a FixedIntervalLoopingCall in neutron/service.py that
diff --git a/neutron/tests/functional/agent/l3/test_legacy_router.py b/neutron/tests/functional/agent/l3/test_legacy_router.py
index f4e6a7d13c8..ab394571416 100644
--- a/neutron/tests/functional/agent/l3/test_legacy_router.py
+++ b/neutron/tests/functional/agent/l3/test_legacy_router.py
@@ -21,6 +21,7 @@ from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants as lib_constants
 
+from neutron.agent.l3 import agent as l3_agent
 from neutron.agent.l3 import namespace_manager
 from neutron.agent.l3 import namespaces
 from neutron.agent.linux import ip_lib
@@ -107,6 +108,32 @@ class L3AgentTestCase(framework.L3AgentTestFramework):
 
         self.assertIsNone(device.route.get_gateway())
 
+    def test_router_processing_pool_size(self):
+        router_info_1 = self.generate_router_info(False)
+        r1 = self.manage_router(self.agent, router_info_1)
+        self.assertEqual(l3_agent.ROUTER_PROCESS_GREENLET_MIN,
+                         self.agent._pool.size)
+
+        router_info_2 = self.generate_router_info(False)
+        r2 = self.manage_router(self.agent, router_info_2)
+        self.assertEqual(l3_agent.ROUTER_PROCESS_GREENLET_MIN,
+                         self.agent._pool.size)
+
+        router_info_list = [r1, r2]
+        for _i in range(l3_agent.ROUTER_PROCESS_GREENLET_MAX + 1):
+            ri = self.generate_router_info(False)
+            rtr = self.manage_router(self.agent, ri)
+            router_info_list.append(rtr)
+
+        self.assertEqual(l3_agent.ROUTER_PROCESS_GREENLET_MAX,
+                         self.agent._pool.size)
+
+        for router in router_info_list:
+            self.agent._router_removed(router.router_id)
+
+        self.assertEqual(l3_agent.ROUTER_PROCESS_GREENLET_MIN,
+                         self.agent._pool.size)
+
     def _make_bridge(self):
         bridge = framework.get_ovs_bridge(utils.get_rand_name())
         bridge.create()