Epistylis infestations occurred on 16 of 32 fish species collected from Mountain Island Lake and Lake Norman, North Carolina, during 1974 and 1975. Percichythids, centrarchids, and ictalurids were the fishes most commonly infested, while infestations were rare on clupeids, cyprinids, and percids. Epistylis was generally more prevalent on fishes during fall (September through November). Percichthyids, followed by centrarchids, had the highest intensity of infestation. Intensity of infestation increased with surface area and length of percichthyids, but not with that of centrarchids. Although the attachment site varied among fish species, Epistylis infestations were restricted primarily to the bony parts. The prevalence of Epistylis on fishes did not correlate with the abundance of Epistylis in the plankton. Dissolved orthophosphate, total phosphorus, alkalinity, and ammonia concentrations were positively correlated with the prevalence of Epistylis on white bass (Morone chrysops), redbreast sunfish (Lepomis auritus), bluegill (L. macrochirus), and largemouth bass (Micropterus salmoides). Total iron and dissolved oxygen concentrations were negatively correlated. Although temperature did not correlate with the pr,evalence of Epistylis on fishes. Epistylis was not found on fishes at water temperatures below 14 C.