Abstract: A leash assembly for a pet collar and a combined collar and leash. A base assembly is permanently or temporarily engaged with the collar. The leash assembly, which has an internal retractor mechanism, is detachably seated on the base assembly and is connected thereto by a short leash. When the leash and base assemblies are engaged, the leash is substantially retracted into the leash assembly. The leash assembly may be grasped and pulled out of engagement with the base assembly thus causing a length of the leash to be unwound from the retractor mechanism. The retractor mechanism includes a lock that is engaged unless a release button on the leash assembly is depressed.