Deltamethrin (DEL) is a synthetic pyrethroid widely used as an insecticide. The aim of our study was to determine the effect of a single exposure of female albino Swiss mice to DEL (at doses of 8.3 mg/kg, 20.75 mg/kg, or 41.5 mg/kg) on parameters of liver and kidney function and activities of antioxidant enzymes in these organs. The activity of alanine transaminase (ALT) in the blood sera of the experimental animals was not signifi cantly elevated after exposure to DEL. Asparagine transaminase (AST) activity was signifi cantly higher in the groups exposed to the moderate and the highest dose of DEL. The levels of creatinine in the blood sera of the experimental animals did not signifi cantly differ among the groups. The activities of superoxide dismuthase (SOD) and glutathione peroxidase (GPx) were significantly reduced in the livers of mice exposed to the highest dose of DEL in comparison with controls. In the kidneys, however, the SOD and GPx activities were significantly elevated after exposure to the highest dose of DEL. In conclusion, DEL produces oxidative stress in the livers and, to a lesser degree, the kidneys of exposed animals.