We have studied 455 consecutive patients with acute myocardial infarction to assess the early and mid-term prognostic value of clinical and laboratory findings in the acute (i.e. Killip classification, arterial PO2, echocardiographic extent of necrotic area) and subacute phase (exercise test, ambulatory ECG). Results showed that clinical examination, blood gas analysis and two-dimensional echocardiography have a high predictivity for in-hospital risk stratification. In particular, two-dimensional echocardiography showed that patients with diffuse wall motion abnormalities had a worse prognosis during the follow-up. Exercise test and, to a lesser extent, ambulatory ECG have well identified patients at risk for new coronary events.