This study investigated the effects of supplementation with Krill oil on levels of pro-oxidant/antioxidant balance markers and levels of pro-inflammatory cytokines in professional rowers submitted to exhaustive exercise.This double-blind study included 17 members of the Polish National Rowing Team. Subjects were randomly assigned a supplemented group (n=9) which received two capsules (500 mg) of Krill oil daily for 6 weeks, or a placebo group (n=8). At the beginning and at the end of preparatory camp, subjects performed a 2000 m maximum effort test on a rowing ergometer. Blood samples were taken from the antecubital vein prior to each exercise test, 1 minute after completing the test, and after 24-hours of rest. The following redox parameters were assessed in erythrocytes: superoxide dismutase (SOD), glutathione peroxidase (GPx), and thiobarbituric acid reactive substances (TBARS) concentration. Additionally, creatine kinase (CK) activity was measured in plasma samples, while tumor necrosis factor (TNF-α) concentrations were measured in the serum.Exercise significantly increased values of SOD, TNF-α and TBARS in both groups, but recovery levels of TBARS were significantly lower in athletes receiving Krill oil compared with the control group.Based on these results we conclude that supplementation with Krill oil (1 g per day) in trained rowers diminished post exercise oxidative damage to erythrocytes during recovery, but had no effect on antioxidant enzymes, TNF-α and serum lipid profiles.