Malignant skin tumors and precancerous lesions have a predilection to be located in the nasal dorsum or sidewall. Although invasive reconstructions have been presented, no simple and suitable method has yet been reported for this area. The flap presented herein, named the lateral nasal advancement flap, is designed on the adjacent lateral region of the sidewall or nasal dorsum and advanced in the medial direction. Two Burow’s triangles are removed in the upper and lower portions of the flap: the upper triangle along the nasofacial sulcus and the lower triangle along the nasofacial sulcus and/or the alar groove. Excellent results were obtained in the two clinical cases described in this report. Neither a trap door deformity nor dog-ears developed in either case. The postsurgical scars followed the aesthetic lines and became inconspicuous. A distinct angle was formed in the nasofacial sulcus without anchor sutures. This surgical procedure is technically simple and is performed under local anesthesia. Although the flap is a cheek-based advancement flap, postsurgical scars do not remain in the cheek; instead, they are located in the nasofacial sulcus and alar groove. The lateral nasal advancement flap is recommended for reconstruction of the nasal sidewall and dorsum.