Channel catfish, Ictalurus punctatus, of five size-classes were stocked into 20, 0.04-ha earthen ponds at a rate of 14,826 fish/ha. Mean initial weights for each size-class were 0.232, 0.458, 0.678, 0.911, and 1.10 kg/fish. Four ponds were randomly allotted to each treatment. A commercial 28% protein diet was fed daily to apparent satiation. When fish reached a predetermined weight in each size-class, all fish were harvested, counted, weighed. Mean final weights for each size-class were 0.435, 0.683, 0.904, 1.16, and 1.36 kg/fish. The data show that smaller fish consumed more feed (as a percentage of body weight) and grew faster than larger fish. The data clearly demonstrate that feed conversion ratio and fish size are highly correlated and that feed conversion ratio increases as fish size increases. These data hold to the basic principle of animal husbandry that smaller animals are fast gainers and fast gain is generally the most efficient gain.