In this work, we studied the effect of reactive oxygen and nitrogen forms on the complexes of NO with hemoglobin under conditions simulating various physiological and pathophysiological conditions. It is well known that reactive oxygen species, reactive halogen species (hypochlorite), reactive nitrogen species (peroxynitrite and nitryl chloride) and other free radicals are involved in inflammatory reactions and in the pathogenesis of various diseases of the most important systems of the human and animal body. Stabilized forms of nitric oxide (NO) bound to hemoglobin: complexes of NO with heme iron (HbNO) and dinitrosyl iron complexes (DNIC) formed on thiol groups of cysteine residues of hemoglobin (Hb-DNIC) are important physiological forms of nitric oxide. Of particular interest for research is the participation of such NO complexes in processes associated with oxidative stress. We showed that peroxynitrite and hypochlorite quantitatively destroy Hb-DNIC, and in the case of hypochlorite, nitrosylation of the hemoglobin heme group does not occur. In addition, the antioxidant effect of Hb-DNIC was shown when interacting with alkoxyl and alkyl peroxide radicals obtained by adding tert-butyl hydroperoxide to a methemoglobin solution, which simulates peroxidation that occurs during oxidative stress. The data obtained make it possible to improve understanding of the role of complexes of nitric oxide with hemoglobin in the balance between antioxidant and prooxidant systems in the body.