Hyperbaric oxygen therapy is neither necessary nor recommended for the support of normal, uncompromised grafts or flaps. However, in tissue compromised by irradiation or in other cases where there is decreased perfusion or hypoxia, hyperbaric oxygen therapy has been shown to be extremely useful in flap salvage. Hyperbaric oxygen can help maximise the viability of the compromised tissue thereby reducing the need for regrafting or repeat flap procedures. The criteria for selecting the proper patients that are likely to benefit from adjunctive hyperbaric oxygen for graft or flap compromise is crucial for a successful outcome. Identification of the underlying cause for graft or flap compromise can assist in determining the proper clinical management and use of hyperbaric oxygen therapy. A number of studies have shown the efficacy of hyperbaric oxygen therapy on enhancement of flap and graft survival in a variety of experimental and clinical situations.