An experiment was conducted to evaluate the impact of cassava (Manihot esculenta, (NR 8082) peel, fermented with wastewater from the fermented cassava pulp, as a substitute for maize in the diet of C. gariepinus juveniles on the growth performance of C. gariepinus. Five iso-caloric and iso-nitrogenous diets were formulated containing 25%, 50%, 75% and 100% maize replacement with cassava peel meal (tagged diets B25, C50, D75, E100). The control was tagged diet A0. Two sets of experiment were designed using the formulated diets. One set, which lasted for 10 days, was designed to monitor the apparent protein digestibility of the diet and the second one to evaluate the growth, nutrient utilization (MWG, FCR, SGR) and the biochemical composition of the fillets of the fish, fed for a period of 8 weeks, in the laboratory. Fermentation significantly reduced (p< 0.05) the phytate (698 mg 100g-1) and cyanide contents (23.5 mg kg-1) of the cassava peels, when compared with those of the unfermented cassava peels (1012 mg 100g-1, 44.6 mg kg-1). The final weight gain (13.47g), daily weight gain (0.19g), percentage weight gain (243.62%), food conversion ratio (5.67), protein efficiency ratio (1.20) and the apparent protein digestibility (APD) of the fish fed with the control diet (diet A0) were not significantly (P>0.05) higher than those of the fish fed diets B25 and C50, but were significantly (P<0.05) higher than those of the fish fed diets D75 and E100. The specific growth rate and survival in all the treatments were not significantly different (P>0.05) from one another. The results revealed that 50% replacement of maize with cassava peel meal (diet C50) can be tolerated by C. gariepinus, without compromising growth, nutrient utilization and digestibility. The percentage survival of the fish fed the control, test diets B25, C50 and D75 were not significantly different (p>0.05) but were significantly different from those fish fed diet E100. It can be concluded that replacing maize with up to 50% replacement level of cassava peels fermented with wastewater from the fermented cassava pulp is not deleterious to growth and nutrient utilization of C. gariepinus. Fermentation might have thus reduced the toxicity and increased the nutrient value of the cassava peels, otherwise regarded as agricultural wastes, and placed it among basal feedstuffs, suitable for replacing maize in C. gariepinus diet.