This experiment was aimed at studying the effect of combined action produced by L-arginine and water-soluble form of quercetin (corvitin) on the markers of oxidative-nitrosative stress in the skin under 30-day intoxication with sodium nitrate (200 mg/kg per day). The combined intraperitoneal administration of L-arginine (500 mg/kg) and corvitin (10 mg / kg in terms of quercetin), once every three days starting from the 15th day of intoxication, reduced the formation of peroxynitrite, production of superoxide anion radical (О-2) by NADPH-dependent (endoplasmic reticulum and NO-synthase) and NADH-dependent (mitochondrial) electron transport chains in the skin tissues, decreased the concentration of compounds reacting with thiobarbituric acid products during incubation in the prooxidant iron-ascorbate buffer solution. The values of these indicators were significantly inferior to the corresponding data obtained by the separate administration of these substances. The combined effect of L-arginine and quercetin in the experimental conditions increased the activity of arginase and superoxide dismutase in the skin tissues, that significantly exceeded the results of the series, in which above mentioned compounds were used separately. We can conclude the combined administration of L-arginine and corvitin is more effective in preventing oxidative-nitrosative stress in the skin of rats exposed to excessive intake of sodium nitrate compared with their separate application, and reduces the production of reactive oxygen and nitrogen species (О-2 and peroxynitrite), increases the antioxidant potential, and enhances the activity of arginase and superoxide dismutase.