Fish species diversity, length-weight relationship and condition factor in Eruwa reservoir were assessed. A total number of 182 fish samples were collected from the artisanal fishermen and identified using morphometric and meristic features. The total length (TL) and standard length (SL) in centimeter (cm) and somatic weight (SW) in gramme (g) were measured using measuring board and weighing balance respectively. Twelve fish species under nine families were identified with family Cichlidae (40.66%) as the most abundant followed by Mormyridae (19.78%). The length-weight relationship revealed allometric growth pattern (b values > 3 or < 3) for all the fish species recorded in Eruwa reservoir. The report on fish species diversity and length-weight relationship in this are ecological indices necessary for sustainable management of fisheries resources in Eruwa reservoir.

Key words: Fish species, diversity, Eruwa reservoir, fisheries management.