ABSTRACTPopliteal artery entrapment and cystic adventitial disease of the popliteal artery are uncommon conditions which have received little attention in the radiology literature. In both conditions, a resting AP arteriogram may be normal and extra techniques are required to demonstrate or exclude abnormality. To show popliteal entrapment a normal or equivocal arteriogram should be repeated with forced extension of the knee and forced plantar flexion of the ankle, and to demonstrate cystic adventitial disease a lateral view may be needed. Failure to perform these views may lead to misdiagnosis and inadequate treatment, with potentially serious consequences.A case of each abnormality is presented and both conditions are described, with a brief review of the literature.