This pilot study was conducted to establish the optimum oral dosage of medroxyprogesterone acetate (Provera) given daily in combination with a fixed dose of piperazine oestrone sulphate (Ogen), as hormone replacement therapy. A group of 32 nonhysterectomized, symptomatic menopausal women were randomly allocated to receive piperazine oestrone sulphate 1.25 mg daily and medroxyprogesterone acetate 2.5 mg, 5 mg or 10 mg daily for a 2-year period. This was an open study and the patients were reviewed at 3-monthly intervals for 2 years. Vaginal bleeding was reported by 58% of patients after the first 3 months of treatment. There was a gradual decline in the reported incidence of bleeding over the following 6 months particularly by women in the 5 mg and 10 mg Provera group. Only 10% of patients were still recording slight bleeding in the 10 mg group at 12 months. By 24 months all the women in the 5 mg and 10 mg Provera groups had ceased bleeding. There were 2 patients in the 2.5 mg Provera group with persistent proliferative endometrium at 24 months. All the remaining patients had atrophic endometrium. There was no significant difference in serum lipid changes between the 3 groups, but there was an overall reduction in total cholesterol, triglycerides and low density lipoprotein cholesterol in all women. There was no significant difference in bone mineral density changes between the groups over the 2-year period. Endometrial protection with increased incidence of amenorrhoea, without significant adverse effects, was seen with the use of 5 mg and 10 mg of provera.