diff --git a/x-pack/plugins/infra/public/components/alerting/metrics/validation.tsx b/x-pack/plugins/infra/public/components/alerting/metrics/validation.tsx
index 0f5b07f8c0e13..2cd59b3381bdc 100644
--- a/x-pack/plugins/infra/public/components/alerting/metrics/validation.tsx
+++ b/x-pack/plugins/infra/public/components/alerting/metrics/validation.tsx
@@ -24,6 +24,7 @@ export function validateMetricThreshold({
       timeWindowSize: string[];
       threshold0: string[];
       threshold1: string[];
+      metric: string[];
     };
   } = {};
   validationResult.errors = errors;
@@ -42,6 +43,7 @@ export function validateMetricThreshold({
       timeWindowSize: [],
       threshold0: [],
       threshold1: [],
+      metric: [],
     };
     if (!c.aggType) {
       errors[id].aggField.push(
@@ -74,6 +76,14 @@ export function validateMetricThreshold({
         })
       );
     }
+
+    if (!c.metric && c.aggType !== 'count') {
+      errors[id].metric.push(
+        i18n.translate('xpack.infra.metrics.alertFlyout.error.metricRequired', {
+          defaultMessage: 'Metric is required.',
+        })
+      );
+    }
   });
 
   return validationResult;