Background: The objective of the present study was to examine the effects of zinc supplementation on the oxidant damage in lung and liver tissues in rats exposed to a 50-Hz frequency magnetic fi eld for 5 minutes every other day over a period of 6 months. Methods: The study included 24 adult male Sprague-Dawley rats, which were divided into the three groups in equal numbers: Group 1, the control group (G1); Group 2, the group exposed to an electromagnetic fi eld (G2); and Group 3, the group, which was exposed to an EMF and supplemented with zinc (G3). At the end of the 6-month procedures, the animals were decapitated to collect lung and liver tissue samples, in which MDA was analyzed using the "TBARS method (nmol/g/protein)", GSH by the "biuret method (mg/g/protein)" and zinc levels by atomic emission (μg/dl). Results: MDA levels in lung and liver tissues in G2 were higher than those in G1 and G3, and the levels in G3 were higher than those in G1 (p<0.01). As for GSH levels, G3 had GSH levels higher than G1 and G2, and G2 had GSH levels higher than G1 (p<0.01). Zinc values in the liver and lung tissues were the highest in the Group 3 and the lowest in the Group 2 (p<0.01). Conclusion: Results of the study indicated that exposure to an electromagnetic fi eld caused cellular damage in lung and liver tissues and zinc supplementation inhibited the infl icted cellular damage. Another important result of this study that needs emphasis was that exposure to an electromagnetic fi eld led to a signifi cant decrease in zinc levels in lung and liver tissues.