There is little information on the effectiveness of secondary prevention interventions in very elderly patients. In this article, the incidence of major cardiovascular events during a 12-month follow-up period in a series of consecutive patients with coronary, cerebrovascular, or peripheral artery disease is analyzed. As of October 2006, 1264 patients had been enrolled. Of these, 324 (26%) were >or=75 years of age. Their incidence rate of 22 events per 100 patient-years (95% CI, 17-28) was over 2-fold the 7.9 (95% CI, 6.2-10) found in those <75 years of age. Among them, only chronic heart failure and diabetes were independently associated with an increased risk for major events, whereas the use of angiotensin II antagonists was associated with a lower risk. Patients >or=75 years of age had an over 2-fold higher incidence of major cardiovascular events. The use of angiotensin II antagonists was associated with a lower risk.