Pseudoaneurysm of the femoral artery occurred in five patients (aged between 61 and 82 years) after catheterization of the artery, four times after percutaneous transluminal angioplasty of the leg arteries and once after left-heart catheterization. The pseudoaneurysms were correctly diagnosed by colour-coded duplex Doppler sonography by demonstrating turbulence within the aneurysm and a connection to the femoral artery with bidirectional shunting. Enough pressure was exerted with the instrument head to stop flow in the aneurysm and its connection to the artery without, however, significantly reducing arterial flow. After 30-35 min flow into the aneurysm had ceased even when the compression was released. Re-examination up to 11 months later (mean of 7.6 months) indicated that the treatment had been successful in all.