Results of recent clinical trials on secondary prevention of ischemic heart disease indicate that judicious, long-term administration of adrenergic beta blockers and platelet-active drugs such as aspirin and Persantine (dipyridamole) would seem to yield protection against mortality associated with acute myocardial infarction, including sudden death. These drugs are beneficial also in prevention of recurrent myocardial infarction, especially among patients with unstable angina. These drugs should be considered as soon as the diagnosis of myocardial infarction or unstable angina is confirmed clinically. In terms of primary prevention of ischemic heart disease and cerebrovascular disease (stroke), the results of the Hypertension Detection and Follow-Up Program provide an excellent set of data on the efficacy of rigorous treatment of hypertension, especially those with mild hypertension. To be effective, treatment must start before there is evidence of target end organ damage, such as left ventricular hypertrophy. Recent data from the Australian Therapeutic Trial in Mild Hypertension also confirms these findings.