The Trial of Preventing Hypertension (TROPHY) demonstrated the feasibility of possibly reducing the incidence of hypertension with the angiotensin receptor blocker candesartan compared with placebo. The long-term benefits of pharmacologic therapy in high-normal blood pressure, or prehypertension are not known, and the long-term effect on health-related quality of life (HRQL) has not been determined. An analysis of covariance model was used to assess treatment differences from baseline in the HRQL scores using Short Form (SF)-36, and component measures at subsequent visits. Of the 809 randomized patients, 734 had both baseline and > or =1 HRQL follow-up assessment: 95% (379 of 397) of patients receiving candesartan and 91% (355 of 388) of patients receiving placebo. There were no statistically significant between-group differences in least-squares mean physical component survey and mental component survey scores or the individual scales at each scheduled visit relative to baseline values (P >.05). In TROPHY, patients with prehypertension had relatively high baseline HRQL, and HRQL was maintained with the angiotensin receptor blocker candesartan over both the 2-year treatment period and a total 4-year trial period.