Cardiac tamponade following coronary perforation is a rare complication in conventional balloon angioplasty. In a series of 8000 dilatations we observed this complication after PTCA in 2 female patients (0.25/1000). In both cases cardiac tamponade occurred 2 h after PTCA of small, in 1 case calcified, coronary arteries during monitoring on the coronary care unit. By immediate percutaneous pericardiocentesis and subsequent drainage by a pigtail catheter we could manage the complication. One patient suffered an acute myocardial infarction 3 days after PTCA because of a subacute occlusion of the perforated vessel.