OBJECTIVE The effects of perindopril treatment on hypertension development and the lifespan of adult spontaneously hypertensive rats (SHR) were studied. METHODS Adult male SHR (aged 15 weeks) were given once a day treatment with 4 mg/kg perindopril by gavage for 12 weeks. Littermates given distilled water were used as controls. The blood pressure and lifespan of these rats were studied. METHODS The systolic blood pressure (SBP), heart rate and body weight of these rats were measured at regular intervals until they died from natural causes. At necropsy macroscopic and microscopic examinations were made of various organs to determine the cause of death. Serum levels of creatinine, urea and protein were also measured. RESULTS Perindopril treatment resulted in the normalization of SBP after 2 weeks of treatment. Withdrawal of the treatment after 12 weeks of treatment caused an elevation of SBP, but the blood pressure of the treated SHR had remained in the normotensive range (< or = 150 mmHg). The heart rate and body weight of the SHR were not affected by the treatment. The average lifespan of the SHR was increased by 12 weeks compared with the control rats. The heart weight, brain lesions and arterial lesions were reduced by the treatment. CONCLUSIONS A 12-week treatment of adult SHR with perindopril was effective in causing a permanent prevention of hypertension, amelioration of some of the tissue damage associated with hypertension and an increase in the lifespan of these rats.