Objective To explore the clinical application of lateral arm free flap in one-stage repair of soft tissue deflect after radical resection of tongue cancer.Methods From June 2019 to September 2021, a total of 32 patients received treatment of lateral arm free flap for one-stage repair of soft tissue defect after tongue cancer radical surgery. Of them, 25 cases were male, 7 were female. As for the pathology, all cases were squamous cell carcinoma. Preoperatively, the perforating vessels in the lateral arm region were positioned by Doppler blood flow detector, and the flap axis was located at 1 cm behind the line between the insertion of the deltoid and the external epicondyle of the humerus. The flaps were designed based on the sizes and shapes of the tongue defects.Results In this group of the 32 patients, the intraoperative flap area size ranged from 7.5 cm×4.0 cm to 14.0 cm×6.0 cm with flap thickness of (0.85±0.40)cm and pedicle length of (8.24±1.37) cm. The median number of perforator was 3 (ranged from 2 to 4). All donor sites of these cases were closed primarily. Flap necrosis occurred on the fourth day after operation in one patient, and was successfully salvaged with a redesigned anterolateral thigh flap. The overall flap survival rate was 96.9%(31/32). No patient received tracheotomy.The postoperative follow-up with a mean period of 11 mouths (ranged from 7 to 22 mouths) revealed no obvious long-term complications, and all patients were satisfied with the shape and function of the flaps.Conclusion With advantages of consistency of perforators, thin and soft texture, simple harvest method, high survival rate and low donor site complications, the lateral arm free flap is suitable to reconstruct tongue with half deflect for tongue cancer patients.