A pusher-occlusive coil delivery assembly 10 that is advanced through a microcatheter 40 to the desired vascular site within a patient. The delivery assembly 10 includes a pushwire 12 which interlocks with the occlusive coil 11 which can be manipulated to detach the occlusive coil 11. When the assembly 10 is positioned at the site, the pushwire 12 is advanced to allow the interlock joint 14, 15 to move out of the delivery sleeve 13 to uncouple the pushwire 12 and the occlusive coil 11.