The present study aimed to investigate the effect of different concentrations of curcumin in fish diet on blood parameters and disease resistance against challenge with pathogenic bacterial agent Pseudomonas aeruginosa. A total number of 120 apparently healthy Tilapia zillii, weighting 35 ± 5 gram were divided into four groups. Each group consisted of 30 fish, each was subdivided into 3 subgroups (10 fish/sub group) in well prepared glass aquaria with water daily changed and fed at 3% body weight per day. The first group fed on basal diet without any supplementation with turmeric powder and served as control group. The second (T1), third (T2) and fourth (T3) groups were fed on the same basal diet supplemented with turmeric powder with different concentrations 2 (0.20%), 5 (0.50%) and 10g/kg (1%) respectively for 30 days. At the end of this period, five fish from all groups were sampled for blood indices for differentiation between basal diet and supplemented diet. After the end of the experiment, fish in all groups were intraperitoneally (IP) challenged with Pseudomonas aeruginosa then blood samples were collected to investigate the effect of turmeric powder on hematological parameters of experimentally infected fish fed onto supplemented and basal diet. The mortality rate after challenging with Pseudomonas aeruginosa were decreased in all treated groups than control group.