diff --git a/drizzle-orm/src/sql/expressions/conditions.ts b/drizzle-orm/src/sql/expressions/conditions.ts
index 506e082396..379c47f79b 100644
--- a/drizzle-orm/src/sql/expressions/conditions.ts
+++ b/drizzle-orm/src/sql/expressions/conditions.ts
@@ -166,16 +166,25 @@ export function or(
 /**
  * Negate the meaning of an expression using the `not` keyword.
  *
+ * A condition that is equal to `undefined` is passed through as `undefined`,
+ * so `not` composes with `and`/`or`, which may return `undefined`.
+ *
  * ## Examples
  *
  * ```ts
  * // Select cars _not_ made by GM or Ford.
  * db.select().from(cars)
  *   .where(not(inArray(cars.make, ['GM', 'Ford'])))
+ *
+ * // Composes with `and`/`or`, which can return `undefined`.
+ * db.select().from(cars)
+ *   .where(not(and(eq(cars.make, 'GM'), eq(cars.year, 1950))))
  * ```
  */
-export function not(condition: SQLWrapper): SQL {
-	return sql`not ${condition}`;
+export function not(condition: SQLWrapper): SQL;
+export function not(condition: SQLWrapper | undefined): SQL | undefined;
+export function not(condition: SQLWrapper | undefined): SQL | undefined {
+	return condition === undefined ? undefined : sql`not ${condition}`;
 }
 
 /**
diff --git a/drizzle-orm/type-tests/geldb/select.ts b/drizzle-orm/type-tests/geldb/select.ts
index e18b74c4b5..0f17e41e3f 100644
--- a/drizzle-orm/type-tests/geldb/select.ts
+++ b/drizzle-orm/type-tests/geldb/select.ts
@@ -440,6 +440,8 @@ const allOperators = await db
 			ne(users.id, 1),
 			or(eq(users.id, 1), ne(users.id, 1)),
 			not(eq(users.id, 1)),
+			not(and(eq(users.id, 1), ne(users.id, 1))),
+			not(or(eq(users.id, 1), ne(users.id, 1))),
 			gt(users.id, 1),
 			gte(users.id, 1),
 			lt(users.id, 1),
diff --git a/drizzle-orm/type-tests/mysql/select.ts b/drizzle-orm/type-tests/mysql/select.ts
index 2dc826af73..62e3f9c2bc 100644
--- a/drizzle-orm/type-tests/mysql/select.ts
+++ b/drizzle-orm/type-tests/mysql/select.ts
@@ -308,6 +308,8 @@ const allOperators = await db
 		ne(users.id, 1),
 		or(eq(users.id, 1), ne(users.id, 1)),
 		not(eq(users.id, 1)),
+		not(and(eq(users.id, 1), ne(users.id, 1))),
+		not(or(eq(users.id, 1), ne(users.id, 1))),
 		gt(users.id, 1),
 		gte(users.id, 1),
 		lt(users.id, 1),
diff --git a/drizzle-orm/type-tests/pg/select.ts b/drizzle-orm/type-tests/pg/select.ts
index dcf99428a6..e809f61738 100644
--- a/drizzle-orm/type-tests/pg/select.ts
+++ b/drizzle-orm/type-tests/pg/select.ts
@@ -439,6 +439,8 @@ const allOperators = await db
 			ne(users.id, 1),
 			or(eq(users.id, 1), ne(users.id, 1)),
 			not(eq(users.id, 1)),
+			not(and(eq(users.id, 1), ne(users.id, 1))),
+			not(or(eq(users.id, 1), ne(users.id, 1))),
 			gt(users.id, 1),
 			gte(users.id, 1),
 			lt(users.id, 1),
diff --git a/drizzle-orm/type-tests/singlestore/select.ts b/drizzle-orm/type-tests/singlestore/select.ts
index 6ec81f6c3f..ae32727647 100644
--- a/drizzle-orm/type-tests/singlestore/select.ts
+++ b/drizzle-orm/type-tests/singlestore/select.ts
@@ -376,6 +376,8 @@ const allOperators = await db
 		ne(users.id, 1),
 		or(eq(users.id, 1), ne(users.id, 1)),
 		not(eq(users.id, 1)),
+		not(and(eq(users.id, 1), ne(users.id, 1))),
+		not(or(eq(users.id, 1), ne(users.id, 1))),
 		gt(users.id, 1),
 		gte(users.id, 1),
 		lt(users.id, 1),
diff --git a/drizzle-orm/type-tests/sqlite/select.ts b/drizzle-orm/type-tests/sqlite/select.ts
index 0140fc19bb..5f54f46a1b 100644
--- a/drizzle-orm/type-tests/sqlite/select.ts
+++ b/drizzle-orm/type-tests/sqlite/select.ts
@@ -387,6 +387,8 @@ const allOperators = db
 		ne(users.id, 1),
 		or(eq(users.id, 1), ne(users.id, 1)),
 		not(eq(users.id, 1)),
+		not(and(eq(users.id, 1), ne(users.id, 1))),
+		not(or(eq(users.id, 1), ne(users.id, 1))),
 		gt(users.id, 1),
 		gte(users.id, 1),
 		lt(users.id, 1),