diff --git a/packages/dbml-core/__tests__/examples/parser/mssql-parse/input/with_check_add_constraint.in.sql b/packages/dbml-core/__tests__/examples/parser/mssql-parse/input/with_check_add_constraint.in.sql
new file mode 100644
index 000000000..285a7cbfc
--- /dev/null
+++ b/packages/dbml-core/__tests__/examples/parser/mssql-parse/input/with_check_add_constraint.in.sql
@@ -0,0 +1,23 @@
+CREATE TABLE [users] (
+  [id] int PRIMARY KEY,
+  [name] varchar(255)
+)
+GO
+
+CREATE TABLE [orders] (
+  [id] int PRIMARY KEY,
+  [user_id] int
+)
+GO
+
+CREATE TABLE [audit_logs] (
+  [id] int PRIMARY KEY,
+  [order_id] int
+)
+GO
+
+ALTER TABLE [orders] WITH CHECK ADD CONSTRAINT [FK_orders_users] FOREIGN KEY ([user_id]) REFERENCES [users] ([id]) ON DELETE CASCADE ON UPDATE SET NULL
+GO
+
+ALTER TABLE [audit_logs] WITH NOCHECK ADD CONSTRAINT [FK_audit_logs_orders] FOREIGN KEY ([order_id]) REFERENCES [orders] ([id])
+GO
diff --git a/packages/dbml-core/__tests__/examples/parser/mssql-parse/output/with_check_add_constraint.out.json b/packages/dbml-core/__tests__/examples/parser/mssql-parse/output/with_check_add_constraint.out.json
new file mode 100644
index 000000000..1b42e2099
--- /dev/null
+++ b/packages/dbml-core/__tests__/examples/parser/mssql-parse/output/with_check_add_constraint.out.json
@@ -0,0 +1,100 @@
+{
+  "tables": [
+    {
+      "name": "users",
+      "fields": [
+        {
+          "name": "id",
+          "type": {
+            "type_name": "int"
+          },
+          "pk": true
+        },
+        {
+          "name": "name",
+          "type": {
+            "type_name": "varchar(255)"
+          }
+        }
+      ]
+    },
+    {
+      "name": "orders",
+      "fields": [
+        {
+          "name": "id",
+          "type": {
+            "type_name": "int"
+          },
+          "pk": true
+        },
+        {
+          "name": "user_id",
+          "type": {
+            "type_name": "int"
+          }
+        }
+      ]
+    },
+    {
+      "name": "audit_logs",
+      "fields": [
+        {
+          "name": "id",
+          "type": {
+            "type_name": "int"
+          },
+          "pk": true
+        },
+        {
+          "name": "order_id",
+          "type": {
+            "type_name": "int"
+          }
+        }
+      ]
+    }
+  ],
+  "refs": [
+    {
+      "name": "FK_orders_users",
+      "endpoints": [
+        {
+          "tableName": "orders",
+          "fieldNames": [
+            "user_id"
+          ],
+          "relation": "*"
+        },
+        {
+          "tableName": "users",
+          "fieldNames": [
+            "id"
+          ],
+          "relation": "1"
+        }
+      ],
+      "onDelete": "CASCADE",
+      "onUpdate": "SET NULL"
+    },
+    {
+      "name": "FK_audit_logs_orders",
+      "endpoints": [
+        {
+          "tableName": "audit_logs",
+          "fieldNames": [
+            "order_id"
+          ],
+          "relation": "*"
+        },
+        {
+          "tableName": "orders",
+          "fieldNames": [
+            "id"
+          ],
+          "relation": "1"
+        }
+      ]
+    }
+  ]
+}
diff --git a/packages/dbml-core/src/parse/ANTLR/ASTGeneration/mssql/MssqlASTGen.js b/packages/dbml-core/src/parse/ANTLR/ASTGeneration/mssql/MssqlASTGen.js
index d4c383030..e09e65f12 100644
--- a/packages/dbml-core/src/parse/ANTLR/ASTGeneration/mssql/MssqlASTGen.js
+++ b/packages/dbml-core/src/parse/ANTLR/ASTGeneration/mssql/MssqlASTGen.js
@@ -1045,6 +1045,45 @@ export default class MssqlASTGen extends TSqlParserVisitor {
     const table = this.data.tables.find((t) => t.name === tableName && t.schemaName === schemaName);
     if (!table) return; // ALTER TABLE should appear after CREATE TABLE, so skip if table is not created yet
 
+    // Handle WITH CHECK/NOCHECK ADD CONSTRAINT FK
+    if (ctx.WITH() && (ctx.CHECK() || ctx.NOCHECK()) && ctx.FOREIGN()) {
+      const constraintName = ctx.constraint ? ctx.constraint.accept(this) : undefined;
+      const localColumns = ctx.fk.accept(this);
+
+      // table_name()[1] is the referenced table (table_name()[0] is the table being altered)
+      const refTableNames = ctx.table_name()[1].accept(this);
+      const { schemaName: refSchemaName, tableName: refTableName } = getSchemaAndTableName(refTableNames);
+
+      // pk is optional - if not specified, assume same column names as fk
+      const refColumns = ctx.pk ? ctx.pk.accept(this) : localColumns;
+
+      const onDelete = ctx.on_delete().length > 0 ? ctx.on_delete()[0].accept(this) : null;
+      const onUpdate = ctx.on_update().length > 0 ? ctx.on_update()[0].accept(this) : null;
+
+      const ref = {
+        name: constraintName,
+        endpoints: [
+          {
+            tableName,
+            schemaName,
+            fieldNames: localColumns,
+            relation: '*',
+          },
+          {
+            tableName: refTableName,
+            schemaName: refSchemaName,
+            fieldNames: refColumns,
+            relation: '1',
+          },
+        ],
+        onDelete,
+        onUpdate,
+      };
+
+      this.data.refs.push(ref);
+      return;
+    }
+
     const columnDefTableConstraints = ctx.column_def_table_constraints() ? ctx.column_def_table_constraints().accept(this) : [];
     const {
       fieldsData, indexes, tableRefs, columnDefaults, checkConstraints,