BACKGROUND Most Fusobacterium necrophorum infections originate in the head and neck region. Infections originating from sites other than the head and neck are rare but are more common in older than in younger adults and have a higher mortality rate than that of infections originating from the head and neck region. CASE REPORT We present the case of a previously healthy 16-year-old female patient who developed bacteremia and pleural effusions with a burn ulcer on the lower leg but had no abnormality in the head and neck region. She sustained a second-degree burn injury on the left shin that remained untreated for several weeks, resulting in the development of Fusobacterium necrophorum bacteremia. She was admitted after developing fever, chest pain, and dyspnea. Blood culture revealed Fusobacterium necrophorum, but no abnormality was noted in the head and neck region, and a second-degree burn was observed on the left shin. She had bilateral pleural effusions assumed to result from a burn ulcer and was intravenously treated with tazobactam/piperacillin and therapeutic thoracentesis. She responded to therapy and made a full recovery. CONCLUSIONS While the origin of the Fusobacterium necrophorum infection in the burn ulcer could not be detected, this case report suggests that burn ulcers are a potential source of systemic Fusobacterium necrophorum infection and highlights the importance of early medical and surgical treatment and antimicrobial therapy.