Twenty-one women (propositi) who expressed serious concerns about changes in body habitus during highly active antiretroviral therapy (HAART) were evaluated by thorough physical examination, anthropometric measurements, and serum lipid and endocrine assays. The same evaluations were carried out in a comparison group of 21 women who received HAART but did not complain of changes in habitus. No significant demographic differences were found between the propositi and the comparison group, nor were there significant differences in CD4 count or plasma viral load (PVL) between the two groups. Lipid analyses were also performed on plasma obtained prior to HAART from 12 of the women. The frequency of changes reported by the 21 propositi were increase in abdominal size (90%), increase in breast size (71%), weight gain of >5 kg (43%), peripheral fat wasting (43%), buttock fat wasting (38%) and development of cervicodorsal fat pad (19%). A subset of patients in the comparison group experienced increase in abdominal size (29%) and weight gain >5 kg (19%), but none experienced clinically detectable peripheral or buttock fat wasting, increased breast size, or development of cervicodorsal fat pads. Mean waist circumference, waist-to-hip ratios (WHR), body fat, and body mass index (BMI) were above the desirable range for women in both propositi and the comparison group. Levels of total cholesterol, triglycerides, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol associated with increased cardiovascular risk were found in 48%, 62%, 45%, and 33%. respectively, of the propositi, with similar findings in the comparison group. Fasting insulin levels were elevated in 4 propositi and 6 of the comparison group; mean insulin levels were within the normal range for both groups. In the comparison of lipids for the subset of patients before and after HAART therapy, HAART was associated with significant increases in total cholesterol, apolipoprotein B, and HDL cholesterol. Changes in body habitus caused by redistribution of fat occur commonly in women receiving HAART. Serum lipid abnormalities also are common during HAART and appear to be as frequent in women who do not experience clinically apparent body fat redistribution as in those who do. The observed changes in body fat distribution and in serum lipid levels are alterations that have been strongly correlated with increased risk for cardiovascular disease. Therefore, an understanding of the basis of these phenomena, and the risks with which they may be associated in this population, will be important for therapeutic decision making in women with HIV disease.