Excess weight gain during both pre- and postnatal life increases risk for obesity in later life. Although a number of gestational and early life contributors to this effect have been identified, there is a dearth of research to examine whether gestational factors and weight gain velocity in infancy exert independent effects on subsequent body composition and fat distribution. The purpose of this study was to test the hypothesis that birth weight, as a proxy of prenatal weight gain, and rate of weight gain prior to 6 months would be associated with total and truncal adiposity at 12 months of age. Healthy, term infants (N=47) were enrolled in the study and rate of weight gain (g/day) was assessed at 0-3 months, 3-6 months, and 6-12 months. Total and regional body composition were measured by dual-energy X-ray absorptiometry at 12 months. Stepwise linear regression modeling indicated that lean mass at 12 months, after adjusting for child length, was predicted by rate of weight gain during each discrete period of infancy (P<0.05), and by maternal pre-pregnancy BMI (P<0.05). Total fat mass at 12 months was predicted by rate of weight gain during each discrete period (P<0.01), and by older maternal age at delivery (P<0.05). Trunk fat mass at 12 months, after adjusting for leg fat mass, was predicted by rate of weight gain from 0-3 months and 3-6 months (P<0.05). Results suggest that growth during early infancy may be a critical predictor of subsequent body composition and truncal fat distribution.