A 76-year-old man presented to the emergency room (ER) with acute onset of coolness, pain, and pallor of the left lower extremity. The patient had a history of hypertension and hypercholesterolemia as well as tobacco use in the past. He denied a history of claudication and had no symptoms related to the right leg. Motor and sensory functions of the left foot were mildly diminished. Femoral pulses were palpable bilaterally, but there were no palpable or Doppler signals distally on the left side, and a prominent right popliteal pulse was noted. The patient was suspected to have an acutely thrombosed left popliteal artery aneurysm.