Aging is a major risk factor for hypertension and cardiovascular disease. Accumulating evidence suggests that telomere length is a marker for biological aging of the cardiovascular system. Telomere length is determined by genetic and environmental factors. Studies in different racial populations are required to determine the prognostic value of telomere length in hypertension and cardiovascular diseases. The main objective of this study was to investigate the association between leukocyte telomere length and the risk and prognosis of hypertension in a Chinese population. The relative telomere length of leukocytes was determined by a quantitative PCR-based method in 767 subjects: 379 healthy controls and 388 hypertensive patients, ages 30 to 80 years. The median telomere length ratio, 0.57 (interquartile range: 0.48 to 0.72), was shorter in hypertensive than in healthy normotensive subjects (0.67; interquartile range: 0.53 to 0.93; P<0.001). After 5 years of follow-up, subjects with shorter telomeres were at a higher risk of developing coronary artery disease than individuals with longer telomeres (odds ratio: 3.315; 95% CI: 1.662 to 6.609; P<0.001). Multivariate analysis showed that short telomere length and hypertension were independent risk factors for developing coronary artery disease. Our data suggest that mean leukocyte telomere length is a potential predictor of coronary artery disease and support the hypothesis that differences in biological aging can contribute to the risk and variability of developing hypertension and cardiovascular diseases.