The purpose of the study is to carry out a comparative analysis of the effect of melatonin (melaxen) and of 3-hy-droxypyridine (mexidol) on antitumor and antimetastatic influence of radiotherapy and oxidative status in mice with Lewis lung carcinoma. Material: Experiments have been carried out on 95 mice of the line C57BI/6 and weight of 20-22 grams. Cyclophosphan has been intraabdominally administered two times in a dosage of 60mg/kg within the interval of 120 hours — 20-30 min before radiotherapy. It has been located on the area of initial tumor in a dosage of 2 Gr at the same time as cyclophosphan injection. Melaxen and mexidol have been intramuscularly injected in the dosage of 45 and 50 mg/ kg for 14 days. Antitumor and antimetastatic effect of the applied therapy and changes in the oxidative status of the animals have been estimated. The results: Melaxen and mexidol do not decrease antitumour and antimetastatic effects of radiotherapy and prevent the activation of free radical processes in animals with tumors. Mexidol has been more effective than melaxen in correction of superoxide dismutase activity in liver. The drugss under the study do not decrease radiotherapy-induced lipid peroxidation in the initial tumor. Conclusion: Melaxen and mexidol do not decrease the therapeutic efficiency of radiotherapy and correct oxidative status in mice with tumor following antineoplastic treatment.