Although the gluteal V-Y advancement flap has been recognized as the most reliable method for management of sacral pressure ulcers, its limited mobility has been a challenging problem. The authors present a new modification of the V-Y advancement flap to overcome the problem. After débridement, a large triangle is designed to create a V-Yadvancement flap on the unilateral buttock and the medial half is elevated as a fasciocutaneous flap, preserving the distal perforators in the muscular attachment. Then an arc-shaped incision is made in the gluteus maximus muscle along with the lateral edge of the triangular flap. The split muscle is elevated at a depth above the deeper fascia until sufficient advancement of the flap is obtained. This full-thickness elevation of the gluteus maximus muscle from the distal (lateral) side avoids the impairment of perforators or their mother vessels and achieves great advancement. Thirty-one patients with sacral pressure defects larger than 8 cm in diameter were treated using this surgical procedure. Overall, 93.5 percent of the flaps (29 of 31) healed primarily. The largest defect that was closed with a unilateral flap was 16 cm in diameter. The present technique accomplishes remarkable excursion of the unilateral V-Y fasciocutaneous flap, with high flap reliability and preservation of the contralateral buttock as well as gluteus maximus muscle function.