Questionnaire surveys were implemented to study the incidence and physicians' knowledge of Vibrio vulnificus infections in Japan. Registered emergency physicians were selected by stratified random sampling for a questionnaire survey. A total of 235 out of 386 physicians (61%) responded to the questionnaire and 12 V. vulnificus septicaemia cases were reported from 10 respondents. The annual estimated number of V. vulnificus septicaemia was calculated as 425 (95 % CI 238-752). The study also revealed that only 15.7 % (95 % CI 11.3-21.0) of responding physicians had a basic knowledge of V. vulnificus infection. Education for both physicians and people in the high-risk group for developing the infection (e.g. immunocompromised, chronic liver disease) will be necessary for the prevention, early diagnosis and appropriate treatment of the disease.