Background: Reduced fetal growth is associated with differences in body composition in adult life that may predispose to cardiovascular disease and diabetes. Most published data are based on simple anthropometric measures, which incompletely describe body composition. Objective: The objective was to assess body composition and fat distribution by using dual-energy X-ray absorptiometry (DXA). Design: This was a case-control study of 64–72-y-old white men (n = 32) with a low (x: 2.76 kg) or high (x: 4.23 kg) birth weight. Results: Compared with the high-birth-weight group, after adjustment for weight and height, the low-birth-weight group had a higher percentage body fat (29.31% compared with 25.33%; P = 0.029) and fat mass (P = 0.039) but a lower fat-free soft tissue (56.32 compared with 59.22 kg; P = 0.024), muscle mass (27.25 compared with 29.22 kg; P = 0.022), and muscle-to-fat ratio. Low birth weight was also associated with a higher trunk-to-limb fat ratio after control for total fat mass (1.42 compared with 1.16; P = 0.005) or percentage body fat (P = 0.041). The same body mass index predicted a greater percentage body fat (P = 0.019) in the low- than in the high-birth-weight group, and the same ratio of trunk-to-limb skinfold thickness (or waist-to-hip ratio) predicted a higher trunk-to-limb fat ratio (P