The use of probiotics is considered effective for survival, growth and enhanced immune response in aquaculture. In the current study, effects of commercially available probiotic (Magic Plus) was investigated on survival, growth and immune response of Mori (Cirrhinus mrigala) in a polyculture system. The experiment was conducted for 90 days on 1200 fingerlings in two groups i.e. control and probiotic supplemented groups each having 600 fingerlings. Control group was fed with 35% protein basal diet without any supplements and the other group was supplemented with commercially available probiotic at the rate of (1012 CFU kg−1 diet). After 90 days, probiotic supplemented group was characterized with significant increase (p < 0.05) in growth parameters like, total weight, total length, %weight gain, specific growth rate and survival growth rate. Immunological indices like, lysozyme activity, white blood cells, total plasma protein level and immunoglobulin (IgM) of supplemented group were also significantly (p < 0.05) enhanced. Moreover, digestive enzymes i.e. cellulase, protease and amylase were also found to be significantly (p < 0.05) hyper-active in probiotic supplemented groups. Haematological parameters like, RBCs, Hb, Hct, MCH and MCHC were also significantly (p < 0.05) increased. Thus, the current study strongly suggests that a commercially available probiotic Magic plus may serve as a healthy and immunostimulating feed additive in C. mrigala culture.