Lake and fish survey data (1991–1992) were compiled for 23 eastern South Dakota natural lakes to provide a basis for preliminary investigation of black bullhead (Ameiurus melas) populations. Survey data contained numerous physical and chemical variables describing lake environments and relative abundance and sue structure of the primary fish species present. Analyses indicated that abundance of black bullheads increased with decreasing lake size (area, depth and volume), increasing nutrients (e.g., total and dissolved phosphorus), and decreasing transparency. Overall, models of biotic variables indicated that black bullhead abundance was negatively associated with abundance of bigmouth buffalo (Ictiobus cyprinellus) and walleyes (Stizostedion vitreum), but positively associated with northern pike (Esox lucius) and common carp (Cyprinus carpio) abundance. Black bullhead sue structure was inversely related to the abundance of common carp, northern pike and yellow perch (Perca flavescens). Black bullhead population size structure was not related to any physicochemical variables. There appeared to be no regulation of black bullhead abundance or size structure by population size structures of other species.