Cardiovascular disease is common in patients on long-term dialysis, and it accounts for 44 percent of overall mortality in this group. We undertook a study to assess long-term survival after acute myocardial infarction among patients in the United States who were receiving long-term dialysis. Patients on dialysis who were hospitalized during the period from 1977 to 1995 for a first myocardial infarction after the initiation of renal-replacement therapy were retrospectively identified from the U.S. Renal Data System data base. Overall mortality and mortality from cardiac causes (including all in-hospital deaths) were estimated by the life-table method. The effect of independent predictors on survival was examined in a Cox regression model with adjustment for existing illnesses. The overall mortality (+/-SE) after acute myocardial infarction among 34,189 patients on long-term dialysis was 59.3+/-0.3 percent at one year, 73.0+/-0.3 percent at two years, and 89.9+/-0.2 percent at five years. The mortality from cardiac causes was 40.8+/-0.3 percent at one year, 51.8+/-0.3 percent at two years, and 70.2+/-0.4 percent at five years. Patients who were older or had diabetes had higher mortality than patients without these characteristics. Adverse outcomes occurred even in patients who had acute myocardial infarction in 1990 through 1995. Also, the mortality rate after myocardial infarction was considerably higher for patients on long-term dialysis than for renal-transplant recipients. Patients on dialysis who have acute myocardial infarction have high mortality from cardiac causes and poor long-term survival.