This study was conducted to investigate effects of fluoride on lipid peroxidation and antioxidant systems in young pigs. Three groups of crossbred barrows about 50 days old were exposed to 100, 250, and 400 mg F–/kg (from NaF) in their diets for 50 days. Serum malondialdehyde (MDA) and nitric oxide (NO) levels were significantly increased, and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were significantly decreased. In thyroid, liver, and kidney tissues, the MDA level was significantly increased, and SOD and GSH-Px activities were significantly decreased. These results suggest that fluoride induces excessive production of NO and reactive oxygen species (ROS), enhances lipid peroxidation, and disturbs the antioxidant system of pigs. Oxidative damage from oxidative stress could therefore be an important pathway for fluoride toxicity in soft tissues.