Distraction osteogenesis has become one of the most widely used methods of correcting craniofacial deformities. In this report we describe a case with Crouzon syndrome treated with Le Fort I distraction osteogenesis using the RED system. The patient was an 11-year 2month-old female with anterior crossbite and maxillary lateral deviation. Her cephalometric radiographs demonstrated craniosynostosis and digital impressions. At the age of 11 years and 6months, a multibracket appliance was used for the presurgical orthodontic treatment of the maxilla. At the age of 13years and 1month, a Le Fort I osteotomy was carried out and the maxilla was distracted using the RED system for 15days. During the distraction, the force vector and the rate of the distraction was adjusted to correct the negative overjet of-5mm and maxillary lateral deviation of 4mm. The external device was left in place for 3weeks for consolidation after the active distraction period, followed by 4months of retention with an orthodontic facial mask. At the age of 13years and 3 months, the multibracket appliance was employed in the mandible. At the age of 15years, 1year and 10 months after distraction, the active orthodontic treatment was finished with acceptable occlusion.