The clinical, angiographic, and procedural findings in 40 in-hospital deaths among 5,000 consecutive percutaneous transluminal coronary angioplasties were reviewed. Compared to the total group, the mortality group had a higher proportion of women, older age, and more extensive coronary disease. Angioplasty was performed as an emergency procedure in 21 of the 40 patients who died. Eighteen presented with an evolving acute myocardial infarction and 17 with unstable angina. Most patients presented in critical condition prior to angioplasty: 18 patients were in cardiogenic shock and 5 patients were on cardiopulmonary resuscitation. Among 13 patients who died following elective angioplasty, the salient feature was acute vessel closure or dissection in 7 patients and failed dilatation of a saphenous vein graft in 4 patients.