Fish production was evaluated at three sites in Guys Run, Virginia, an 8-km, second-order Appalachian stream, from August 1979 through July 1980. Mean standing stock ranged from 21.4 kg˙hectare-1upstream to 47.4 kg˙hectare-1downstream. Annual production by the fish taxocene was estimated at 28.4, 31.6, and 39.6 kg˙hectare-1˙year-1in the upper, middle, and lower sections, respectively. Brook trout Salvelinus fontinalis, mottled sculpin Cottus bairdi, blacknose dace Rhinichthys atratulus, and bluehead chub Nocomis leptocephalus were the dominant species, accounting for 87 to 99% of total fish production in the stream. Annual production : biomass (P/B) ratios ranged from 0.6 to 1.6 and were consistent with previously determined values for the same or similar species in other small streams.