To minimize the functional disability and cosmetic deformity, adequate reconstructive surgery is essential after surgical extirpation of the head and neck malignancies. Several methods were reported, using free graft, local flap, regional flap and compound myocutaneous flap, previously. In our dept, the authors performed reconstructive surgery using forehead flap after surgical extirpation of the mouth floor cancer on Mar. 1986. Result was good with excellent viability, good tongue mobility with minimal articulation problem and relatively good cosmetic result.