Immunostimulants are substances which stimulate the specific as well as non-specific defence mechanism of fish. This also enhances resistance against pathogens and reduces stress. The present study was conducted to evaluate the immune-stimulatory effects of different Immunostimulant incorporated diets such as brewer's yeast, vitamin C, vitamin E and ginger which were equated against commercial diets. The experiment was conducted in 20 fibreglass tanks each of 400 L capacity with 50 fishes per tank. The experiment was subjected to five treatments and four replicates using completely randomized design (CRD). Experiment was conducted for 90 days. After 90 days of feeding experiment, experimental fishes were challenged intra-peritoneally with pathogenic bacteria, Aeromonas hydrophila. Results indicated that out of the five tested diets, ginger incorporated diet was significantly increase the Hb, RBC,WBC and Hct in both pre- as well as post-challenge study (P < 0.05). The outcome concludes that the Zingiber officinale powder can act as good immunostimulant which may possibly enhance the non-specific immunity and disease resistance of striped catfish against Aeromonas hydrophila infection.