Abstract: PURPOSE To investigate the clinical outcomes of composite lateral arm free flap to reconstruct soft tissue defect after oral cancer ablation. METHODS Fifteen cases of soft-tissue defects were reconstructed using composite lateral arm free flap from January 2011 to December 2013. Color Doppler ultrasound blood flow detector was used to avoid variation of posterior radial collateral artery (PRCA). Composite flaps were designed according to the direction of PRCA, shape and area of the soft-tissue defect, which were over condylus lateralis humeri, with areas ranged from 4 cｍ×5 cm-11 cm×5 cm and an average vascular pedicle length of 10cm. Primary closure was achieved on all donor sites. RESULTS Fourteen flaps survived while vascular crisis was found in one flap 1 day post operation. The flap was replaced after an invalid salvation. All patients were followed up over 12 months, no recurrence was found. All patients achieved good recovery of morphology and functions with only 2 reporting local numbness of donor sites, which were relieved after 6 months.CONCLUSIONS Composite lateral arm free flap, with consistent anatomy, suitable thickness and reliable blood supply, is a proper method to reconstruct postoperative soft tissue defect of patients with oral carcinoma.