This study was performed to assess the effects of natural plant-based additive in juvenile of Nile tilapia (Oreochromis niloticus) reared in in-pond hapas under field conditions. The fish (73 g) were stocked in 2-m3 hapas, in triplicates, at a density of 20 fish m-3 (40 fish hapa-1). 2 isonitrogenous (30% CP), isoenergetic (17MJ kg-1) extruded commercial tilapia diets were tested at 0 (control) and 0.50 g of the botanical blend (Phyto AquaNityTM , PAN) kg-1 diet. The diets were fed to the fish at a daily rate of 2-3% of their body weight (BW), twice a day over 80 days. The growth performance and tissue composition were not significantly affected by dietary treatments. However, feed efficiency was significantly improved in fish fed PAN-based diet. Immune and antioxidant responses were enhanced with supplemental PAN. Furthermore, digestive and hepatic enzyme activities were improved as well. The activities of lysozyme, alternative complement, phagocytic cells, phenoloxidase, superoxide dismutase, glutathione peroxidase, and catalase were all significantly increased (P<0.05), while malondialdehyde decreased, in the supplemental PAN group. The length of the intestinal folds and the number of goblet cell counts also significantly increased in fish fed PAN. Overall, Phyto AquaNity improves feed efficacy, immune and antioxidant parameters. This natural additive is suggested to be included in tilapia feed to support the optimum feed efficiency and health of Nile tilapia.