The present study aimed to investigate the effect of different concentrations of garlic and/or curcumin in fish diet on growth performance, total blood protein, albumin, globulin, phagocytic activity, phagocytic index and disease resistance against challenge with pathogenic bacterial agent Pseudomonas fluorescens. Fish were separated into six experimental groups of 0% (control),1% garlic, 2%garlic, 1% curcumin, 2% curcumin and (1% garlic plus 1% curcumin mixed group) fed at 3% body weight per day. Results showed that garlic and curcumin supplementation have significant improvement on growth performance compared to control except the garlic and curcumin mixed group. Total protein and globulin have significantly increased in all treated groups than control, but both of total protein and globulin were dropped with increasing the concentration of either garlic or curcumin. Phagocytic activity and index were significantly higher in all groups than the control. The mortality rate after challenging with Pseudomonas fluorescens were decreased in all treated groups than the control except the garlic curcumin mixed group. It could be concluded that inclusions of garlic or curcumin in Oreochromis niloticus (O. niloticus) diets improve the growth Performance and immunity as was indicated by significant Increase of total protein, globulin, phagocytic activity and index of phagocytes which enhanced the resistance of challenged fish to Pseudomonas fluorescens.