The risk of occurrence or aggravation of aortic valve regurgitation after percutaneous aortic valvuloplasty was evaluated by angiography in 50 consecutive patients: 17 men, 33 women, mean age 77.6 years. In all cases angiography was performed with a pigtail catheter, trying to get the catheter in the same position for injections before and after dilatation. Forty-one patients showed no changes from the predilatation situation: aortic regurgitation was absent in 10 cases, minimal in 30 cases and moderate in 1 case. Minute leakage developed in a patient who had no aortic valve regurgitation prior to dilatation. Regurgitation decreased or subsided in 8 patients, i.e.: moderate leakage became minimal in 6 cases and minimal leakage completely disappeared in 2 cases. In the last 8 patients (3 men, 5 women, mean age 76 years) heart rate and transaortic diastolic pressure gradient were identical before and after dilatation, which means that the angiographic reduction of leakage was due to better closure of the valve. Aortic valve dilatation seems to carry a low risk of major aortic regurgitation. In patients who require percutaneous valvuloplasty for tight aortic valve stenosis, the presence of a small or moderate aortic leakage should not preclude the procedure from being performed.