The Society for Cardiac Angiography maintains a registry of intracoronary streptokinase therapy (IC-SK) in patients with acute myocardial infarction. Between July 1981 and August 1984, 1,029 patients were entered into the registry. The baseline and clinical characteristics of patients were determined, the early results of therapy were evaluated, and baseline characteristics of those in whom reperfusion was achieved were compared with those in whom it was not. Multivariate discriminant analysis was used to identify the predictors of reperfusion and hospital mortality. The overall rate of reperfusion was 71.2%. Reperfusion was positively associated with hypotension, absence of cardiogenic shock and early treatment. The hospital mortality rate for all patients was 8.2% and was higher for women and the elderly. The hospital mortality was significantly lower among patients in whom reperfusion was achieved compared with those in whom it was not (5.5% vs 14.7%, p less than 0.0001) and for several high-risk subgroups. Thus, coronary artery reperfusion induced by IC-SK significantly reduces hospital mortality in high-risk patients with acute myocardial infarction. High-risk patients in whom reperfusion fails with IC-SK therapy should be considered for early coronary angioplasty or coronary artery bypass surgery.