Abstract Background Studies have reported that pharmacologic interventions with candesartan or ramipril could reduce the risk of hypertension among prehypertensive subjects free of clinical cardiovascular disease (CVD), however, the cost-effectiveness and long-term cardiovascular risk of drug treatment among these population is unclear. Method A Markov state-transition model was developed to simulate a hypothetical cohort of Chinese adults with high-range prehypertension (130–139/85–89 mm Hg) but without CVD. Data on the incidence of CVD and hypertension was obtained from corresponding risk equations. Utility and disease-related costs were obtained from published literatures. Robustness and uncertainty was evaluated using deterministic and probabilistic sensitivity analyses. Results Compared with placebo, drug treatment resulted in delaying the development of hypertension by nearly 12 years and reducing the absolute incidence of hypertension by 32.01% over lifetime. The cumulative incidence of coronary heart disease, stroke and heart failure were reduced and survival was improved from 28.46 to 28.80 years. The average incremental cost effectiveness ratio for drug treatment was $12,994 per quality-adjusted life-year and the value was mostly sensitive to the effect size of treatment and age starting treatment. At a willingness-to-pay threshold of > 3 × China gross domestic product per capita in 2014, there was a 30.48% chance that drug treatment would remain cost-effective and a low chance of being cost-effective if relative risk of treatment on hypertension was larger than 0.64. Conclusion Drug treatment for prehypertension may help stem the current epidemic of hypertension among Chinese adults free of CVD, which may in turn reduce CVD complications and potentially be cost effective.