Vibrio vulnificus infection is a fatal disease occurring after the consumption of seafood in patients with underlying liver disease. Inflammation of the skin, subcutanous fat and fascia disseminates from the lower extremity to the trunk and upper extremity Infectious myositis caused by vibrio vulnificus is rare, and its MR imaging findings have not been reported. We report these in a case of infectious myositis caused by vibrio vulnificus involving both lower extremities.