Moringa oleifera leaves can be used to improve the health of fish in general. To understand the effectiveness of moringa leaves powder addition in improving the immunity of Pangasianodon hypophthalmus toward Aeromonas hydrophila attack, This study has been conducted from June to September 2022. The fish was fed with moringa powder enriched pellets and then infected with A.hydrophila. There were 4 treatments applied, namely Negative Control (no moringa and no infection), Positive Control (no moringa, infection), T1 (5 g/kg, infection), T2 (10 g/kg, infection), and T3 (15 g/kg, infection). The fingerlings of P.hypopthalmus (3.5±0.5g BW) were reared for 45 days (1 fish/4L water) and fed 3 times/day, 5% of body weight. A.hydrophila was infected through injection (0.1 mL of 108 CFU/mL) on the 31st day. The hematology of the fish was checked on the 31st day and the 14th day after infection (or on the 45th day of the research). Results showed that after being treated with moringa for 30 days, the hematology of fish in all treatments showed almost no difference. However, the Phagocytic Index was slightly higher in the moringa-treated fish, they were around 20.33% (in NC and PC) and 23.33-25.67% (in T1, T2, and T3) respectively. On the 14th day after the infection, the Phagocytic Index increased to 26.67%; 29.00%, and 30.33% in T1, T2, and T3 respectively. There was no Positive Control fish that survive by the end of the experiment, while 88.89 – 97.77% of moringa-treated fish survive, and the infection wound was completely cured. Data obtained indicate the Moringa addition in the fish feed pellets is effective to improve the immunity of P.hypopthalmus against A.hydrophila infection