In this study, it is investigated that immunostimulant effects of laurel powder by dietary intake on rainbow trout. After 14 days of adaptation on a control diet 3 groups of rainbow trout were fed the experimental diets containing 0.5 and 1% laurel leaf powder for 21 days. The fish were then switched back to the control diet. Non-specific immunity was investigated at the end of the 21 day experimental feeding period and then again 42nd, 63rd days later. The non-specific immune parameters, extracellular and intracellular respiratory burst activities, phagocytosis in blood leukocytes, lysozyme and total plasma protein level were evaluated. The result of this study showed no effect on respiratory burst, lysozyme activity and total plasma protein levels. Phagocytic activity of fish fed diet supplemented 0.5 and %1 laurel, respectively was significantly higher than other groups. However, there is no correlation between dosages of laurel.