It is well known that the main factor which contributes to the relapse of orthognathic surgery for Cleft Lip and Palate (CLP) patients is post-operative scar on hard and soft palate of maxilla. Therefore, to compensate the amount of relapse, though it cannot be the perfect way to prevent orthodontic, orthopedic relapse, the Le-fort I osteotomy of maxilla and set-back osteotomy of mandible are generally carried-out simultaneously. We are to review the factors contribute to the relapse of CLP patients after orthognathic surgery through this clinical case : The relapse of Skeletal Class III tendency immediately after orthognathic surgery for grown up CLP patients.