Objective To report the clinical results and the advantages/disadvantages of anterolateral thigh flap (ALT) and forearm flap (FAF) in reconstruction of head and neck defect after cancer ablation. Methods 20 FAFs and 12 ALTs were performed to repair the head and neck tumor ablation defects. Of the 20 FAFs, 7 were used for repair of the through and through buccal defects, 4 for circumferential bypopharyngeal defects, 2 for plate defects, 1 for parotid area skin defect, 4 for floor of the mouth defects, and 2 for defect, of the base of the tongue, while of the 12 ALTs, 3 were used for repair of the defects of the base of the tongue, 4 for plate defects, and 5 for the floor of the mouth and/or lower gum defects. Survival of the flaps, function of the recipient site, and impact to the donor site were compared between these two groups to analyze the advantages/disadvantsges and key technique details of these two flaps. Results 19 FAFs totally survived. Vascular crisis occurred in 2 cases of FAF, of which 1 flap survived after conservative treatment, while the other 1 developed partial necrosis. All the 12 ALTs survived, without vascular crisis. 2 of the 14 planed ALTs were abandoned and replaced by FAFs, of which 1 because of absence of the perforating branch and the other 1 because of injury of the perforating branch. Secondary defects of the ALTs could be closed primarily, while secondary defects of the FAFs should be closed with skin grafts. Conlusion Both ALT and FAF can be performed with high survival rate. Each has its own advantages. Selection of the donor site deponds on situation of the defect and purpose of the reconstruction.