Necrotising fasciitis is an infection which makes a progressif facial necrosis with a high mortality rate. A 53 year old man who had a history of type 2 diabetes along the 18 years was operated urgently with a prediagnosis of necrotising fasciitis of the left thigh and after we saw the facial necrosis intraoperatively, certain diagnosis of the necrotising fasciitis was decided. Following the early antibiotherapy and one-stage wide surgical debridement, patient had no problem in his left lower extremity after the 15 months follow-up period.