Fish species diversity and abundance were examined over a 3 year period at 6 study sites within a single watershed in the Piedmont of South Carolina. The fish community was dominated by 3 cyprinid species, but included 22 species. Average Shannon-Weaver fish species diversity estimates ranged from 0.15 to 1.87, and were related to substrate diversity. Fish species diversity increased downstream, and decreased in relation to silt in the substrate and frequency of drying. Fish abundance increased downstream and with depth, but was also influenced by substrate characteristics known to influence distribution of aquatic insects.