The main existing indications for hyperbaric oxygenation (HBO) therapy are well known. But there are some works where the effect of HBO was studied in such illnesses which are not considered as indications for this method. So, the problem of the usage of the HBO under the threat of rejection of cutaneous flaps or grafts is under the study now (Wattel F et al, 1990). Proceeding from the peculiarities of the therapeutic effect of HBO (Tabrah FL et al, 1994), with the help of HBO we have optimised the treatment of patients (after the replantation of extremity segments and autotransplantation of tissue complexes) who where operated using microsurgical equipment. 24 patients with the given pathology were treated in HBO unit during 1994–97 years. HBO sessions began in a day after the operation and where administrated once a day. The highest pressure of isopression was 1.7–2.0 ATA; the duration, 40 min. The average number of sessions for each patients was 8–10. The complete accommodation of replanted segments and transplants was noted in all the patients. Nevertheless the major accommodation factor of amputated extremity segments is a careful fulfilment of vascular anastomosis. It guarantees the reconstruction of blood flow in arteries and veins. So we consider it justified use HBO in patients with critical ischemia term of abjuncted extremity segments and prolonged ischemia of complex flaps with their autotransplantation.