Abstract: Fingerlings of Chrysichthys nigrodigitatus were fed four isocaloric diets at different crude protein levels to determine the optimum protein requirement of the species. Significant differences (p< 0.05) were recorded for the growth indices, weight gain and average daily growth rate, the highest values obtained for the fingerlings fed the 35% crude protein diet. Similarly, the estimated cost of production was best (and least) in the 35% protein diet. The nutrient utilization parameters had variable results among the treatments. While there was no significant difference in values obtained for apparent feed conversion ratio, the nitrogen metabolism showed significant variation, the 35% crude protein diet giving the best result. The quadratic regression analysis of weight gain on the protein intake indicated that the optimum protein requirement of the fish is 35.06%. It is therefore, concluded that 35% crude protein is optimal in the diet of of fingerlings of Chrysichthys nigrodigitatus