diff --git a/specification/securityinsights/resource-manager/Microsoft.SecurityInsights/preview/2019-01-01-preview/SecurityInsights.json b/specification/securityinsights/resource-manager/Microsoft.SecurityInsights/preview/2019-01-01-preview/SecurityInsights.json
index 8f5a0dbce22a..062f46155e9a 100644
--- a/specification/securityinsights/resource-manager/Microsoft.SecurityInsights/preview/2019-01-01-preview/SecurityInsights.json
+++ b/specification/securityinsights/resource-manager/Microsoft.SecurityInsights/preview/2019-01-01-preview/SecurityInsights.json
@@ -1411,6 +1411,54 @@
                     }
                 }
             }
+        },
+        "/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/{operationalInsightsResourceProvider}/workspaces/{workspaceName}/providers/Microsoft.SecurityInsights/aggregations/{aggregationsName}": {
+            "get": {
+                "x-ms-examples": {
+                    "Get aggregative data for all cases under the defined workspace, between the time range if specified.": {
+                        "$ref": "./examples/aggregations/GetCasesAggregations.json"
+                    }
+                },
+                "tags": [
+                    "Aggregations"
+                ],
+                "description": "Get aggregative result for the given resources under the defined workspace",
+                "operationId": "CasesAggregations_Get",
+                "parameters": [
+                    {
+                        "$ref": "#/parameters/ApiVersion"
+                    },
+                    {
+                        "$ref": "#/parameters/SubscriptionId"
+                    },
+                    {
+                        "$ref": "#/parameters/ResourceGroupName"
+                    },
+                    {
+                        "$ref": "#/parameters/OperationalInsightsResourceProvider"
+                    },
+                    {
+                        "$ref": "#/parameters/WorkspaceName"
+                    },
+                    {
+                        "$ref": "#/parameters/AggregationsName"
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/Aggregations"
+                        }
+                    },
+                    "default": {
+                        "description": "Error response describing why the operation failed.",
+                        "schema": {
+                            "$ref": "#/definitions/CloudError"
+                        }
+                    }
+                }
+            }
         }
     },
     "definitions": {
@@ -2797,6 +2845,36 @@
                     "description": "Determines whether the setting is enable or disabled."
                 }
             }
+        },
+        "Aggregations": {
+            "type": "object",
+            "description": "The aggregation.",
+            "discriminator": "kind",
+            "allOf": [
+                {
+                    "$ref": "#/definitions/Resource"
+                },
+                {
+                    "$ref": "#/definitions/AggregationsKind"
+                }
+            ]
+        },
+        "AggregationsKind": {
+            "type": "object",
+            "description": "Describes an Azure resource with kind.",
+            "properties": {
+                "kind": {
+                    "type": "string",
+                    "description": "The kind of the setting",
+                    "enum": [
+                        "CasesAggregation"
+                    ],
+                    "x-ms-enum": {
+                        "name": "AggregationsKind",
+                        "modelAsString": true
+                    }
+                }
+            }
         }
     },
     "parameters": {
@@ -2970,6 +3048,14 @@
                 "$ref": "#/definitions/Settings"
             },
             "x-ms-parameter-location": "method"
+        },
+        "AggregationsName": {
+            "name": "aggregationsName",
+            "in": "path",
+            "required": true,
+            "type": "string",
+            "description": "The aggregation name. Supports - Cases",
+            "x-ms-parameter-location": "method"
         }
     }
 }
\ No newline at end of file
diff --git a/specification/securityinsights/resource-manager/Microsoft.SecurityInsights/preview/2019-01-01-preview/examples/aggregations/GetCasesAggregations.json b/specification/securityinsights/resource-manager/Microsoft.SecurityInsights/preview/2019-01-01-preview/examples/aggregations/GetCasesAggregations.json
new file mode 100644
index 000000000000..f67eaa7781d2
--- /dev/null
+++ b/specification/securityinsights/resource-manager/Microsoft.SecurityInsights/preview/2019-01-01-preview/examples/aggregations/GetCasesAggregations.json
@@ -0,0 +1,35 @@
+{
+    "parameters": {
+        "api-version": "2019-01-01-preview",
+        "subscriptionId": "d0cfe6b2-9ac0-4464-9919-dccaee2e48c0",
+        "resourceGroupName": "myRg",
+        "workspaceName": "myWorkspace",
+        "operationalInsightsResourceProvider": "Microsoft.OperationalInsights",
+        "aggregationsName": "cases"
+    },
+    "responses": {
+        "200": {
+            "body": {
+                "id": "/subscriptions/d0cfe6b2-9ac0-4464-9919-dccaee2e48c0/resourceGroups/myRg/providers/Microsoft.OperationalInsights/workspaces/myWorkspace/providers/Microsoft.SecurityInsights/aggregations/Cases",
+                "name": "Cases",
+                "type": "Microsoft.SecurityInsights/aggregations",
+                "kind": "CasesAggregation",
+                "properties": {
+                    "aggregationBySeverity": {
+                        "totalCriticalSeverity": 13,
+                        "totalHighSeverity": 14,
+                        "totalMediumSeverity": 4,
+                        "totalLowSeverity": 15,
+                        "totalInformationalSeverity": 26
+                    },
+                    "aggregationByStatus": {
+                        "totalNewStatus": 42,
+                        "totalInProgressStatus": 30,
+                        "totalResolvedStatus": 2,
+                        "totalDismissedStatus": 1
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file