The microsurgical free vascularized latissimus dorsi myocutaneous flap was successfully applied in the correction of long-term flexion contracture of the left knee due to scalding burn on the paralyzed leg from poliomyelitis. The patient was a 21 year old male, who suffered from 70° of flexion contracture of the left knee due to scalding burn at the age of 7 years. He has had flaccid paralysis of both legs since the age of 2 years. and not been able to ambulate with bilateral crutches and long leg braces. However after posterior capsulotomy, and successful microsurgical free vascularized latissimus dorsi myocutaneous flap, his left knee could be fully extended and fitted into bilateral long leg braces. So he was able to walk with bilateral crutches and discharged from the hospital on the day of 5th week after admission. Therefore microsurgical free vascularized latissimus dorsi myocutaneous flap is recommended for large soft. tissue defects such as those arising from posterior capsulotomy of knee joint used in the correction of flexion contracture from scalding burn scar upon the paralyzed legs from poliomyelitis.