External fixators for fracture stabilization or limb lengthening cause complications such as pseudoaneurysm, acute ischemia, bleeding, compartment syndrome, and arterio venous fistula. This is a report of a patient who sustained open fracture of both bones of the right leg and the recovery period was complicated by a rare complication where migration of the proximal pin of external f ixator into the popliteal vessels and rupture of pseudoaneurysm with popliteal vessels injury after a trivial trauma.