Plasma lipids and lipoproteins were measured in 21 post-menopausal women after 4 and 8 months of continuous treatment with an orally administered combination of oestradiol and medroxyprogesterone acetate. The mean concentrations of cholesterol and low-density-lipoprotein (LDL) cholesterol were reduced by 12% (P < 0.001) and 11% (P < 0.01), respectively, after 4 months of treatment and by 9% (P < 0.05) and 12% (P < 0.05) after 8 months. The mean level of high-density-lipoprotein (HDL) cholesterol showed an initial fall of 5% (P < 0.05) after 4 months and then increased by 13% (P < 0.05) after 8 months of treatment. The plasma triglycerides level oscillated around the baseline value, but the changes were not statistically significant. Indexes such as the HDL-cholesterol/LDL-cholesterol and cholesterol/HDL-cholesterol ratios, which are considered to be good indicators of atherogenic risk, showed changes towards patterns considered to be beneficial. Although the clinical significance of these changes remains uncertain at present, it seems clear that an oestradiol and medroxyprogesterone combination administered continuously produces biochemical changes which are regarded as protective against cardiovascular disease. Additionally, the endometrial inertness attributed to the continuous oestrogen-progestogen therapy would warrant its use as a good alternative in post-menopausal replacement therapy.