We report a case of nonclostridial gas gangrene in a dentist caused by S. intermedius that was isolated from the oral cavity. A 42-year-old male dentist was admitted in April 2000, complaining of high fever and severe pain in the right axilla and chest. Pain and swelling started two weeks before without history of trauma and there was suppurative discharge five days before admission. The patient incised and drained his axilla and stitched the wound by himself using instruments in his dental office. On admission his axilla and front chest were swollen with palpable crepitations of the skin. He was diagnosed to have gas gangrene by X-ray, CT-scan and laboratory findings. He was treated with surgical debridement of necrotic tissue immediately. Antibiotics, that were negative on DLST (Drug Lymphocyte Stimulation Test) were administered intravenously. He also received hyperbaric oxygen therapy (2.5 ATA, 1 hr, 10 times). After a secondary closure of the wound was performed, the patient was discharged without any further complications 55 days after his initial operation. S. intermedius is one of the members of the Streptococcus milleri group. S. milleri group are indigenous bacteria separated from the oral cavity, intestine and vagina and are reported as a possible pathogen of the gas gangrene or myonecrosis. In this case, S. intermedius infection is recognized as an occupation related disorder.