More than 250 patients, mainly with locally advanced tumors of the head, neck and breast were treated with a I MeV beam of fast neutrons emitted from a BR-10 reactor. The fast neutron contribution to the total dose of the radical component of complex gamma-neutron therapy was 20-40%. Said modality was shown to improve the results of treatment for laryngeal and breast tumors. The 5-year actuarial survival following complex gamma-neutron therapy for laryngeal cancer was 89.25, while in controls--65.2% (p < 0.005). The 5-year actuarial overall survival in breast cancer patients treated with fast neutrons was 66.5%: gamma-neutron therapy alone--46.0% (p < 0.05).