To assess the impact of entrainment of larval fishes at steam generating electrical power plants, samples were collected in Lake Erie. In 1975, 1976 and 1977 the Western Basin was sampled and in 1978 the sampling was concentrated in the Central Basin. The 1975, 1976 sampling permitted calculation of an estimated impact of entrainment of adult yellow perch and emerald shiners using the adult approach. In 1978, 25 species were collected from the Central Basin in Ohio waters of which 82.4% were gizzard shad/alewives, emerald and spottail shiners. Field collections yielded higher estimates of entrainment than in-plant collections and significant differences were found between entrainment estimates from field samples and from in-plant samples from the Central Basin for gizzard shad, rainbow smelt, carp and freshwater drum.