The current study was conducted to investigate the stress effect of high stocking density and to evaluate the efficiency of Glycyrrhiza glabra extract (LE) and protexin concentrate (PC) in Oreochromis niloticus. A total of 360 Nile tilapia fingerlings were divided into 5 groups. The 1st and the 2nd groups were stocked at a rate of 10 fish/ aquarium (control) and 20 fish/aquarium (HSD), respectively. The 3rd group (20 fish/aquarium fed on basal diet supplemented with 200 mg/kg protexin) (HSD + PC). The 4th group (20 fish/aquarium fed on basal diet supplemented with 500 mg/kg LE) (HSD + LE). The 5th group (20 fish/aquarium fed on basal diet supplemented with 200 mg/kg PC+ 500 mg/kg LE) (HSD + PC + LE). HSD group had the lowest body weight, specific growth rate and feed intake. After the Aeromonas hydrophila challenge, fishes from HSD recorded the highest mortality, while the opposite occurred in supplemented groups. It could be concluded that supplementation of LE, PC separately or in combination can positively attenuate the undesirable effects of HSD on growth, antioxidant, immunity and bacterial disease resistance of fish.