The channel catfishIctalurus punctatusis abundant in Lake Oahe, South Dakota, providing a minor sport fishery. Because of it's population size, channel catfish undoubtedly influence the trophic ecology of Oahe Reservoir. However, little research has been conducted on channel catfish since the years following dam closure. We studied the food habits of channel catfish in Lake Oahe during 1991 and 1992. Food habits were evaluated using the relative importance (RI) index. Channel catfish fed on a variety of prey, but aquatic insects dominated the diet for all sizes of fish sampled. Terrestrial insects, zooplankton, and vertebrates (toads and fish) largely comprised the remainder of the diet.