Postradiation changes in the tissues and delayed wound healing were presumed by all hyperbaric medicine societies including Undersea and Hyperbaric Medical Society (UHMS) and European Committee for Hyperbaric Medicine (ECHM) as one of the basic indications for hyperbaric oxygen therapy (HBO). The authors estimated the influence of hyperbaric oxygen on molecular, biochemical and cellular changes in injured tissues including that after radiotherapy. Reviewing the references the authors tried to state the actual role of HBO in oncology of head and neck tumors. The authors referred their experiences in adjuvant therapy of head and neck neoplasms with HBO: 1] postradiation changes of head and neck after adjuvant radiotherapy (7 cases) and after primary radiotherapy (1 case); 2] delayed postoperative wound healing (1 case).