We describe the procedure for reconstruction of a defect on the buccal mucosa and the prolabium with a buccal mucosal transposition flap and an artificial dermis graft. The preparation of the flap started with an incision extending from the border of the defect to the corner of the mouth. The pivot point of the flap was near the stump of the excised prolabium. Only the buccal mucosa was elevated from the buccal surface. It was transposed onto the defect of the prolabium and sutured to the edges of the defect. After reconstruction of the prolabium, the artificial dermis was trimmed and sutured to the mucosal and skin edges of the surgical defect. This is an easy and minimally invasive procedure to cover a defect of the buccal mucosa and the prolabium. In our experience, the wound healed with good, functional, and cosmetic results.