Mean platelet volume (MPV) is increased in various cardiovascular diseases. We sought to determine the prognostic value of MPV for hypertension. We performed a retrospective cohort study. Baseline characteristics were measured in 9168 individuals without hypertension, and the follow-up period was 9 years. Hypertension was confirmed in 2881 participants during the follow-up period. When the participants were grouped according to MPV quartiles, the hazard ratio of future hypertension gradually increased across the MPV quartiles. The hazard ratios of hypertension for the II, III and IV (high) vs. I (low) quartiles of MPV were 1.13 (95% confidence interval (CI) 1.01-1.25, P=0.027), 1.25 (95% CI 1.12-1.39, P<0.001) and 1.40 (95% CI 1.26-1.55, P<0.001), respectively. In multivariate Cox regression analysis, MPV predicted hypertension independently of age, sex, platelet count, waist circumference, drinking, systolic blood pressure and creatinine levels. The present study indicated that elevated MPV is associated with increased incidence of hypertension independent of other risk factors, which suggests that platelet activity may play a role in hypertension incidence.