Popliteal artery entrapment by an anomalous band of the gastrocnemius muscle is an uncommon but apparently under-diagnosed syndrome. Historically, arteriography has been used to diagnose this condition, but the standard method may not demonstrate arterial deviation or differentiate entrapment from other conditions that affect the popliteal artery, such as cystic adventitial disease and thrombosed popliteal artery aneurysms. Computed tomography has become increasingly useful to vascular surgeons in elucidating arterial disorders of the popliteal fossa. This case demonstrates the usefulness of computed tomography evaluation in the diagnosis and management of popliteal artery entrapment.