Effect of exogenous Melatonin on oxidant and anti-oxidant systems in alcohol-induced liver damage was examined. 36 male rats were used in 3 groups, control (Group 1), ethanol-administration (Group 2), and ethanol and melatonin (10 mg/kg, i.p.) administration (Group 3). Liver damage was demonstrated histopathologically in Group 2 whereas livers from Group 3 showed a slight damage indicating melatonin’s protective effect. There was a significant increase (p<0.01) in the level of malondialdehyde (MDA), a marker of lipid peroxidation (LPO) of Group 2 (11.04±2.09 nmol/mg protein) compared to control group (6.74±1.12 nmol/mg protein) whereas melatonin administrated group had MDA levels (7.97±1.22 nmol/mg protein) close to control. There was an inverse correlation between liver damage and glutathion peroxidase (GSH-Px), superoxide dismutase (SOD) levels. A significant increase (p<0.001) in liver selenium (Se) levels in Group 3 (2.20±0.36 µg/gr wet tissue) compared to Group 2 (1.78±0.35 µg/gr wet tissue) which was close to control (3.04±0.33 µg/gr wet tissue) was observed. In conclusion, melatonin causes a significant reduction in increased LPO levels, enhances anti-oxidant enzymes effectiveness in alcohol-induced liver damage. Tissue Se level seems to have an antioxidant contribution by affecting anti-oxidant enzymes.