In the period January 1, 1992, to December 31, 1993, 1518 patients were submitted to coronography and nine developed a false aneurysm at the point of entrance of the catheter in the femur. In 23 of 1377 patients who were subjected to coronary arteriography there was subsequently formation of a similar aneurysm. There were eight women and 24 men with an average of 63±11 years. The false aneurysms developed between one or 14 days, mean days 3.6, after the catheterization. Doppler ultrasonography showed a swirling flow in the area involved and color Doppler evaluation demonstrated a to and fro waveform. In 13 patients multiple pseudoaneurysms (49 in total), were also observed. All patients were submitted, upon diagnosis, to ultrasonographic guided compression of the lesion. The procedure was successful in4249 aneurysms and in 2532 patients, usually after one to three cycles of compression lasting 6 to 8 minutes. The procedure was unsuccessful in those patients who were under treatment of high doses of anticoagulants.In conclusion, the authors are of the opinion that US-Doppler guided compression of the vascular lesions following a cardiac catheterization via the femoral artery, and in particular false aneurysms, is the procedure of choice in their treatment.