BACKGROUND: Data on the effect of hormone replacement therapy (HRT) on blood pressure (BP) in hypertensive menopausal women are limited. OBJECTIVE: To investigate the association between HRT and longitudinal change in BP in hypertensive menopausal women. PATIENTS AND METHODS: We recruited a total of 161 hypertensive menopausal women (mean age = 52.2 +/- 6.6 years) attending the hypertension clinic in our hospital that requires HRT to attenuate the effect of menopause symptoms. These women were followed for up tp 36 months, being evaluated every 6 months with measurements of their BP, weight and the number of drugs needed to control their BP. We also measured serum cholesterol levels before and after the initiation of HRT. RESULTS: The systolic BP remained unaffected throughout the whole follow-up period, whereas the diastolic BP was slightly reduced at 6, 24 and 36 months. This decrease was accompanied by an increased need for antihypertensive medication throughout the entire follow-up period, while the body weight also increased at 18, 24, and 36 months. No particular differences were noted with respect to ethnicity, history of pre-eclampsia or surgical menopause, before and after the initiation of HRT. Serum cholesterol levels remained unchanged during the evaluation period. Oestrogen-progestogen combination therapy use was associated with a lower diastolic BP and a smaller number of antihypertensive drugs compared to other forms of HRT. CONCLUSION: HRT use does not have an adverse gross effect on BP in hypertensive menopausal women who need it, although there may be an increased need for antihypertensive therapy during the 36-moth follow-up period of our study.