The objective of this study was to evaluate the effects of three different rates of kefir on growth performance and immunoglobulin (IgM) levels of Çoruh trout (Salmo coruhensis). The experiment was carried out with the four following treatments: Control group (not supplemented kefir), D1, D2 and D3 (kefir supplemented diet 10, 20, 40 g kg-1 fish body mass, respectively). Condition factor (CF), food conversion ratio (FCR), survival rate, and specific growth rate (SGR) were monthly determined and IgM level was measured at the end of the 4 months. Survival ranged from 88.2 to 89.1%, and was independent of dietary treatments (P>0.05). The highest specific growth rate was found for the fish fed D2; although, there was no significant difference in growth parameters between the control, the fish fed D1, D2 and D3 (P>0.05). However, diets contained kefir (D1, D2) increased immunoglobulin level in S. coruhensis (P<0.05). It can also be concluded that kefir is crucial for fish production as a potential probiotic.