A fish feeding study was conducted in a closed recirculation water system for 12 weeks; to evaluate the effect of feeding Nile tilapia (Oreochromis niloticus) on treated soybean products. Extruded full fat soybean (EFFSB), Germinated Soybean seeds (GSB), Germinated and heated soybean seeds (GHSB) replaced 50 and 100% of the Soybean meal in the control diet. Growth performance, feed utilization and body composition of 315 tilapia fingerlings (an average initial weight of 1.2 gl fish) were used. Fish were randomly distributed into 21 aquaria (15 fingerlingsl aquarium); the water volume in each aquarium was 60 liters. Fish were fed daily at a rate of 1.7 % of fish metabolic body size (w^0.8) with isonitrogenous (30% CP) and isocaloric (4200 kcal GEl kg diet). Each diet was given to three replicate aquaria. The following experimental treatments were tested Tl (100% soybean meal (Control), T2 (50 % of the soybean meal was replaced by EFFSB), T3 (100% EFFSB), T4 (50 % of the soybean meal was replaced by GSB), T5 (100% GSB), T6 (50 % of the soybean meal was replaced by (GHSB), T7 (100% GHSB). Results revealed that the highest specific growth rate (3.1 %/day) was recorded by T2, whereas the lowest value (1.61 %1 day) was recorded by treatment 5. The survival rates of treatments 2, 3, I were 97.78, 95.55 and 95.55%, respectively. The worst survival rate (51.1 %) was obtained by T5. Better feed conversion ratio (FCR) was occurred when fish was fed treatments I (control), 2, 3, 6 and 7 than fish groups fed treatments 4 and 5 (P>0.05). Protein efficiency ratio (PER) were found to be high when fish were fed diets containing EFFSB. The highest value of dry matter in whole fish body was recorded for T3, whereas the lowest value was noticed for T5. Body crude protein content of treatments I, 2 and 4 and 6 were significantly higher than the other treatments. Body fat content of fish fed T3 was higher significantly than the other treatments (P<0.05). From the previous results we can conclude that germination of soy seeds without heating had minor effect on trypsin inhibitor which affected negatively the growth performance, feed utilization and carcass composition of tilapia fish when included in its diets.