We assessed incidence and risk factors of cardiovascular events in 265 patients undergoing allogeneic hematopoietic stem-cell transplantation (HSCT) between 1980 and 2000 and who survived at least 2 years. Results were compared with a cohort of 145 patients treated during the same period with autologous HSCT. The median age of patients with allogeneic HSCT at last follow-up was 39 years, and median follow-up was 9 years. Eighteen (6.8%) patients after allogeneic and 3 (2.1%) patients after autologous HSCT experienced an arterial event. The cumulative incidence of first arterial event after allogeneic HSCT was 22.1% (95% CI, 12.0-40.9) at 25 years. The cumulative incidence 15 years after allogeneic HSCT was 7.5% as compared with 2.3% after autologous HSCT. Adjusting for age, risk of an arterial event was significantly higher after allogeneic HSCT (RR 6.92; P =.009). In multivariate analysis, allogeneic HSCT (RR: 14.5; P =.003), and at least 2 of 4 cardiovascular risk factors (hypertension, dyslipidemia, diabetes, obesity) (RR: 12.4; P =.02) were associated with a higher incidence of arterial events after HSCT. Thus, long-term survivors after allogeneic HSCT are at high risk for premature arterial vascular disease. HSCT might favor the emergence of established risk factors, such as hypertension, diabetes, and dyslipidemia.