The species composition and relative abundance of fishes in West Point Reservoir, a main stem Chattahoochee River reservoir, changed after impoundment in 1975. Strong year classes of gizzard shad, threadfin shad, largemouth bass, black crappie, bluegill, brown bullhead, carp, bowfin, and many sunfishes were produced in 1975. Sixteen species disappeared from the present reservoir region; 11 were not collected after impoundment, and 5 others disappeared during the first year. Forty-three species were found in the reservoir 2 years after impoundment, of which 6 did not occur in preimpoundment sampLes from the West Point Reservoir region. By 1977 the dominant species were gizzard shad, threadfin shad, bluegill, redbreast sunfish, and black crappie.