Agenesis of the popliteal artery has not been described as a vascular anomaly in the lower extremity. This case report describes congenital absence of the popliteal artery discovered during operative exploration after a traumatic injury to the lower extremity. The preoperative arteriogram suggested acute occlusion of the popliteal artery. Intraoperative exploration and arteriography were consistent with agenesis of the popliteal arterial segment, and postmortem examination confirmed these arteriographic and intraoperative observations. Embryologically, failure of the middle portion of the sciatic artery to persist would account for this anomaly. A review of series reporting congenital anomalies of the lower extremity vasculature failed to discover previous mention of this particular abnormality. Agenesis of the popliteal artery should be included among those vascular anomalies that may affect management of lower extremity vascular disease.