To determine the value of color Doppler in the diagnosis of vascular complications resulting from cardiac catheterization 5 consecutive patients, with the clinical suspicious of vascular iatrogenesis potentially requiring surgical repair, were analyzed. In 2 patients a femoral mass developed after a diagnostic catheterization but 3 patients underwent previously an interventional catheterization technique. In 3 patients color Doppler readily visualized a systolic jet originated in the femoral artery entering an anterior echo-free cavity, and a reversal flow in diastole, suggesting a femoral pseudoaneurysm. In 1 patient the clinical diagnosis of arteriovenous fistulae was confirmed by color Doppler which demonstrated a continuous turbulent flow within the femoral vein. In the remaining patient a diagnosis of simple femoral haematoma was made after the demonstration of a relatively echogenic structure overlying the femoral artery and vein but not interfering with their flows. In the 3 patients with femoral pseudoaneurysms and in the patient with arteriovenous fistulae the diagnosis was confirmed by angiography and during surgery. Our preliminary findings underscore the value of color Doppler, using the technology currently available in echocardiographic laboratories, in the differential diagnosis of vascular complications after cardiac catheterization.