This study evaluated the use of fermented mango (Mangifera indica) seed meal (FMS) to substitute yellow maize in the practical diet for Nile tilapia, Oreochromis niloticus fingerlings (4.76±0.32 g). Five iso-nitrogeneous (35% crude protein) and approximately iso-energetic (3400 ME Kcal/kg) dietsin which yellow maize was replaced by FMSat 0% (FMS0/Control diet), 25% (FMS25), 50% (FMS50), 75% (FMS75) and 100% (FMS100) levels were formulated. The fish were fed on the diets at 5% body weight for 84 days. Alkaloids were highest (2.32%) among the anti-nutritional factors analyzed in FMS, while oxalate (0.84%) was lowest. Potassium was highest (8.91 mg/g) among the minerals, while copper was lowest (0.01 mg/g). Weight gain, specific growth rate and feed conversion ratio were similar (p>0.05) in fish fed diets FMS0 and FMS50. The fish fed diet FMS0 had the highest protein efficiency ratio (1.88). Protein digestibility decreased (p0,05). Oblik hranidbe riba FMS0 imao je najveći omjer djelotvornih bjelančevina (1,88). Probavljivost bjelančevina smanjila se povećanjem dijetetskog FMS-a, dok se probavljivost ugljikohidrata povećala. Dobiveni rezultati pokazuju mogućnost zamjene žutog kukuruza sjemenom fermentiranog manga u hrandibi tilapija do 50% bez da taj oblik hranidbe utječe na rast, iskoristivost nutritivnih sastojaka i probavljivost bjelančevina prilikom hranidbe mlađi tilapije
