Brook trout fry in Lawrence Creek consumed more chironomids, simuliids, and ephemeropterans than trichopterans or amphipods during their first 6 months of life. Diets of fry from different sections of the stream were similar. Fry captured from upstream sections were consistently longer (5 to 12 mm) than those taken from downstream sections. This differential is explained on a basis of preferential upstream migration of larger fry during the period of the study.