diff --git a/packages/google-cloud-monitoring/google/cloud/monitoring_v3/query.py b/packages/google-cloud-monitoring/google/cloud/monitoring_v3/query.py
index 18ea0573515d..da7d74dbd060 100644
--- a/packages/google-cloud-monitoring/google/cloud/monitoring_v3/query.py
+++ b/packages/google-cloud-monitoring/google/cloud/monitoring_v3/query.py
@@ -206,6 +206,8 @@ def select_projects(self, *args):
     def select_resources(self, *args, **kwargs):
         """Copy the query and add filtering by resource labels.
 
+        See more documentation at: https://cloud.google.com/monitoring/api/v3/filters#comparisons.
+
         Examples::
 
             query = query.select_resources(zone='us-central1-a')
@@ -273,8 +275,14 @@ def select_metrics(self, *args, **kwargs):
 
             metric.label.<label> = "<value>"
 
-        However, by adding ``"_prefix"`` or ``"_suffix"`` to the keyword,
-        you can specify a partial match.
+        However, by adding ``"_notequal"`` to the keyword, you can inequality:
+
+        ``<label>_notequal=<value>`` generates::
+
+            metric.label.<label> != <value>
+
+        By adding ``"_prefix"`` or ``"_suffix"`` to the keyword, you can specify
+        a partial match.
 
         ``<label>_prefix=<value>`` generates::
 
@@ -596,7 +604,15 @@ def _build_label_filter(category, *args, **kwargs):
 
         suffix = None
         if key.endswith(
-            ("_prefix", "_suffix", "_greater", "_greaterequal", "_less", "_lessequal")
+            (
+                "_prefix",
+                "_suffix",
+                "_greater",
+                "_greaterequal",
+                "_less",
+                "_lessequal",
+                "_notequal",
+            )
         ):
             key, suffix = key.rsplit("_", 1)
 
@@ -617,6 +633,8 @@ def _build_label_filter(category, *args, **kwargs):
             term = "{key} < {value}"
         elif suffix == "lessequal":
             term = "{key} <= {value}"
+        elif suffix == "notequal":
+            term = "{key} != {value}"
         else:
             term = '{key} = "{value}"'
 
diff --git a/packages/google-cloud-monitoring/tests/unit/test_query.py b/packages/google-cloud-monitoring/tests/unit/test_query.py
index 20010ff60b37..754a2dc6561f 100644
--- a/packages/google-cloud-monitoring/tests/unit/test_query.py
+++ b/packages/google-cloud-monitoring/tests/unit/test_query.py
@@ -517,6 +517,11 @@ def test_metric_labels(self):
         )
         self.assertEqual(actual, expected)
 
+    def test_metric_label_response_code_not_equal(self):
+        actual = self._call_fut("metric", response_code_notequal=200)
+        expected = "metric.label.response_code != 200"
+        self.assertEqual(actual, expected)
+
     def test_metric_label_response_code_greater_less(self):
         actual = self._call_fut(
             "metric", response_code_greater=500, response_code_less=600