Introduction: FG is rapidly progressive infectious disease, is seen especially in the genital area and is a localized form of necrotizing fasciitis. Cellulitis also is a mild disease of skin and extremities. Presentation of Case Report: We report a case involving a 71-years-old woman with history of rashes which were started in two days ranging from the thigh to breast who referred to us extensive pelvic cellulitis mimicking Fournier's gangrene. She has taken intensive care unit, followed up with carefully antibiotics and dressings. She recovered well and was discharged in two weeks. Discussion: In the diagnosis and treatment of Fournier's gangrene, has advanced significant improvements since description by Jean-Alfred Fournier in 1883. However, its morbidity and mortality is still at 25% to 35%. Conclusion: In patient with FG or as in our case, there should be early diagnosis and treatment should be quickly.