Abstract: Objective To observe the outcome of relaying anterolateral thigh (ALT) perforator flap in resurfacing the donor site wound following free anteromedial thigh (AMT) perforator flap transfer for reconstruction of defect after oral tumor radical resection. Methods From January 2013 to January 2016, 28 patients with oral tumor underwent radical resection in our hospital, leaving defects with size ranged from 6.5 cm×3.5 cm to 11.0 cm×7.5 cm which were reconstructed by free AMT perforator flaps with size ranged from 7.0 cm×4.0 cm to 12.0 cm×8.0 cm. All the arteries of AMT perforators were anastomosed with superior thyroid arteries, while the venae comitants were anastomosed with superior thyroid venae or internal jugular venae. The donor site wounds of free AMT perforator flaps were reconstructed by relaying ALT perforator flaps with size ranged from 8.0 cm×3.5 cm to 14.0 cm×7.5 cm. The relaying ALT perforator flap and wound edge were closed directly with layer interrupted suture. Postoperatively, the patients stayed in bed and received diet through nasal feeding tube, and the ordinary diet and lower extremity exercise were carried out from one week after operation. Results The AMT and ALT perforators existed consistently in all patients. In 16 patients the venae comitants of AMT perforator arteries were anastomosed with superior thyroid venae in end-to-end fashion, while in 12 patients with internal jugular venae in end-to-side fashion. All flaps survived uneventfully about 2 weeks after operation, and the wounds healed smoothly. All patients were followed up for 6 to 30 months after operation. The sites repaired with free AMT perforator flaps were not bulky in appearance, with two-point discrimination distances ranged from 8 to 15 mm. The movement of tongue was not obviously affected, and patients could speak and eat normally. The texture and color of the sites repaired with relaying ALT perforator flaps were close to those of the adjacent tissue, and the two-point discrimination distances of the sites repaired with relaying ALT perforator flaps were ranged from 7 to 12 mm. The function of thigh was not obviously affected, and patients could walk normally and do related daily activities. Conclusions Reconstruction of defect after oral tumor radical resection with free AMT perforator flap can achieve good outcome, and wound in the donor site of free AMT perforator flap repaired with relaying ALT perforator flap can achieve good appearance and function recovery.