The study was conducted in 18 male rats of Wistar strain. The rats were divided into three groups: a control group, which received distilled water and two experimental groups, which received sodium fluoride (10 mg/kg of body mass/24 h) in water solution. Animals in the second experimental group received 3 mg of vitamin E/rat/24 h and 2 mg methionine/rat/24 h. The experiment lasted 35 days. In supernatants obtained after homogenization of rat liver slices, the activity of the following enzymes was assayed: fructose-1,6-biphosphate aldolase (ALD) malate dehydrogenase (MDH), lactate dehydrogenase (LDH), sorbitol dehydrogenase (SDH) the activity of glutathione peroxidase (GPx), glutathione transferase (GST) and glutathione reductase (GR). Pathomorphological evaluation was conducted on preparations made by standard paraffin method, followed by staining with hematoxylin and eosin. The administration of antioxidants counteracted changes in the activity of the enzymes and the morphological abnormalities of the liver induced by NaF. Antioxidants may be important in preventing toxicity of fluoride compounds.