The purpose of this study was to determine the loss of visceral fat during weight loss program with diet only or diet plus exercise in premenopausal obese women (age 44±6 yr) . One hundred seventeen women (body mass index 29±3 kg /m²) were divided into diet only group (DO, n=40) and diet plus exercise group (DE, n=77) . DE was further divided into two groups: a group with a small change in VO₂max (DE₁, n=26) and a group with a large change in VO₂max (DE₂, n=51) . Height, weight, fat mass, %fat, fat-free mass (FFM), abdominal total fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA) and VO₂max (ml/kg FFM/min) were measured before and after weight loss. The changes of weight, fat mass, %fat were significantly larger in DE than in DO. No difference was found in the changes of weight, fat mass, %fat between the DE₁ and DE₂. Percentage of change in VFA was significantly larger in DE₂ (41±15%) than in DE₁ (31±16%) . These data suggest that both weight-loss programs (DO and DE) contribute to a remarkable decrease in visceral fat. Addition of exercise training, which would induce an improvement in VO₂max, to dietary restriction, may elicit a greater effect on visceral fat.