Hyperbaric oxygen therapy (HBOT) is approved in the United States for 14 accepted indications, which are approved by the HBOT committee of the Undersea and Hyperbaric Medical Society and by the Food and Drug Administration. These indications are also used worldwide. HBOT is a mode of medical treatment in which the patient is situated in an enclosed pressure chamber and breathes 100% oxygen at a pressure greater than 1 atmosphere absolute (ATA), with the usual therapeutic pressure set at greater than 1.4 ATA. In South Korea, an expanded knowledge base and formalized education in HBOT do not exist, and numerous HBOT devices are old and nearing the cessation of operation, although HBOT has undergone refinement, with an increased understanding of mechanisms of action and clinical applications. Furthermore, there is no specific board certification of HBO competence for emergency, critical care, and surgical physicians and technicians in South Korea. We summarize the existing literature on the uses of HBO with the aim of enhancing the understanding of this therapeutic technique.