Forty-eight male Wistar albino rats were allocated to the four groups such that each comprised 12 animals. The first group was maintained as the control. In group 2, evening primrose oil was administered at a dose of 0.1mL rat(-1) day(-1) (approximate to 500mg kg(-1) bw) into the stomach via gavage, whilst in group 3 sodium arsenide was administered at a concentration of 100mg L-1 in ad-libitum drinking water for 30days. The fourth group was given 0.1mL rat(-1) day(-1) evening primrose oil into the stomach via gavage plus 100mg L-1 of sodium arsenide in ad-libitum drinking water for 30days. At the end of the 30th day, tissue (liver, lung, kidney, brain, heart, spleen, and testis) and blood samples were collected from each group. Malondialdehyde (MDA) and nitric oxide (NO) levels and superoxide dismutase, catalase and glutathione peroxidase activities were measured in the samples. Exposure to arsenic in rats causes oxidative stress by increasing lipid peroxidation (increase of MDA and NO levels) and altering the activity of antioxidant enzymes. Evening primrose oil did not have any adverse effects. Furthermore, it was ascertained that the administration of arsenic with evening primrose oil reduced the severity of oxidative stress.