BACKGROUND: Previous analysis in a prospective, population-based cohort reported reduced weight gain in children fed extensively hydrolyzed casein (eHF-C) formula during the first year of life but showed no effect on growth between 1 and 6 y of life. No studies have been conducted in children up to the age of 10 y. OBJECTIVE: The objective was to investigate potential differences in body mass index (BMI) over the first 10 y of life between infants fed within the intervention period of the first 16 wk of life with partially hydrolyzed whey (pHF-W), extensively hydrolyzed whey (eHF-W), eHF-C, or cow-milk formula (CMF) and infants exclusively breastfed (BF) within the intervention period. DESIGN: This was a prospective, randomized, double-blind trial in full-term neonates with atopic heredity in the German birth cohort German Infant Nutritional Intervention (GINI) followed through the first 10 y of life. Analyses of absolute and World Health Organization (WHO)-standardized BMI trajectories for 1840 infants [pHF-W (n = 253), eHF-W (n = 265), eHF-C (n = 250), CMF (n = 276), and BF (n = 796)] were conducted according to intention-to-treat principles. RESULTS: Except for the previously reported slower BMI gain in infants fed with eHF-C formula within the first year of life, no significant differences in absolute or WHO-standardized BMI trajectories were shown between the pHF-W, eHF-W, eHF-C, CMF, and BF groups thereafter up to the age of 10 y. CONCLUSIONS: Extension of the follow-up period from 6 to 10 y for this randomized controlled trial showed no long-term consequences on BMI for the 4 infant formulas considered. These data need to be confirmed in future studies.