A 24-year-old female diabetic patient was hospitalized because of ketoacidosis and a necrotic wound on the hand. Debridement and antibiotic therapy failed to halt the process. After demonstration of Mucor in cultures from the wound, the patient underwent extensive surgery and amphotericin B was administered. When the necrotic process continued despite these measures, adjunctive hyperbaric oxygen (100% O2 at 2.5 ATA for 90 minutes) was administered daily for a total of 21 treatment sessions. She gradually improved, and at 2 months follow-up most of the wound had healed. Although the mortality rate of cutaneous/soft-tissue zygomycosis is markedly lower than that of the rhinocerebral form, morbidity is still considerably high. Successful use of hyperbaric oxygen has been reported in rhinocerebral zygomycosis, and it may have been of benefit in this high-risk patient by preventing local and systemic spreading of the fungus. This report is the first case of the use of hyperbaric oxygen for cutaneous/soft-tissue zygomycosis. It is suggested that hyperbaric oxygen be considered for this indication in diabetic patients as an adjunct to surgery and amphotericin B.