A leash for domestic animals comprising a box-shaped body that houses a cord-winding pulley and a handle with open annular profile that ends at the free ends with rotational pins inserted from opposite sides in suitable housings obtained on the sides of a basically rectangular short pipe joined to said box-shaped body. The handle is provided with a button that stops and releases the pulley with the interposition of suitable return means. The handle is composed of two C-shaped semi-parts, each of them ending with one of said rotational pins at one end and with fast coupling and uncoupling mechanisms at the other end.