We reviewed the timing and mechanism of death in 1,184 consecutive patients with acute myocardial infarction (AMI) treated with primary angioplasty from 1984 to 1995. Of 98 deaths, 48 (49%) occurred early on day 0 or 1. The mechanisms of death were pump failure in 60 patients (61%), reinfarction in 7 patients (7.1%), left ventricular rupture in 5 patients (5.1%), arrhythmia in 3 patients (3.1%), other cardiac causes in 5 patients (5.1%), stroke in 6 patients (6.1%), anoxic encephalopathy in 7 patients (7.1%), and procedure-related deaths in 5 patients (5.1%). The strongest predictors of mortality were cardiogenic shock and unsuccessful reperfusion. Our data indicate that mortality after primary angioplasty, like thrombolytic therapy, is highest in the early hours and is usually due to pump failure. In contrast to thrombolytic therapy, the incidence of death from myocardial rupture and bleeding complications is low. Future treatment strategies will need to focus on the large number of patients with early death due to pump failure, especially patients with cardiogenic shock.