We examined 1-y weight and height gains among 238 rural Bangladeshi children aged 3-11 y old to address the hypothesis that dietary protein composition is associated with growth velocity. Energy-adjusted total protein and energy-adjusted protein from sources other than cereal (animal, pulses, and vegetables) were associated with higher weight gains, after adjustment for age, sex, land ownership, diarrhea, acute respiratory infections, other fevers, nutritional status at the beginning of the study, and average body mass index of the mother [daily intake of energy-adjusted noncereal protein (beta +/- SE): 14.2 +/- 6.4 g.y-1.g-1, P = 0.03; total protein: 13.1 +/- 6.3 g.y-1.g-1, P = 0.04; and protein as percent of energy intake: 39.5 +/- 20.2 g.y-1.% of energy from protein-1, P = 0.05]. These findings are compatible with the hypotheses that protein intake may be a limiting factor for weight gain in this population, or that higher protein intake from animal sources (mostly fish) and legumes (lentils and peas) may be accompanied by higher intakes of limiting micronutrients.