The activities of antioxidant enzymes in rats fed with hot-smoked rainbow trout (Oncorhynchus mykiss) was investigated. Four diets containing fresh and hot-smoked rainbow trout flesh and vitamin were prepared and commercial pellet food purchased. Four groups of rats were fed with the diets for 28 days. Body weight was checked weekly. No significant (P > 0.05) differences were found in weight between groups. Malondialdehyde (MDA) values of group B and group D were found to be significantly increased (P < 0.05). Differences in glutathione peroxidase (GPX) and glutathione reductase (GR) values were not significant (P > 0.05) between groups. The difference in superoxide dismutase (SOD) and catalase (CAT) values was found to be significant (P < 0.05). The hot smoked process led to significant changes as decreased in the antioxidant enzymes activities. Our results indicate that determination of MDA, GPX, GR, SOD and CAT parameters in blood may help to point out cancer risk in humans.