Telomere length is related to cellular aging and cardiovascular disease. Nevertheless, the specific role of cellular aging in this process is still unclear. The aim of this report was to analyze the prognostic value of telomere length in men admitted for acute coronary syndrome. Telomere length was measured by quantitative polymerase chain reaction in peripheral blood leukocytes of 203 men classified into 2 groups: those aged 50 to 75 years and those >75 years. Clinical follow-up had been done for >600 days, and a prognostic combined event was defined. In men aged 50 to 75 years, we found a statistically significant worse prognosis in patients with short telomeres (log-rank: 5.22, p <0.05) but not in men >75 years (log-rank: 0.01, p = 0.91). Cox analysis confirmed short telomeres in men aged 50 to 75 years as an independent prognostic risk factor. In conclusion, telomere length is a good predictor of cardiovascular prognosis in men admitted for acute coronary syndrome, but this relation depends on the chronological age of the population studied.