The reconstruction of extensive soft tissue defects from pressure ulcers is a great challenge. Resurfacing such defects with like tissues and minimizing morbidities are important. Here we present our surgical experience using a novel modified keystone flap for pressure ulcer patients. We retrospectively reviewed the data of 13 consecutive cases reconstructed with the modified keystone flaps between March and December, 2017. The mean dimensions of the reconstructed defect were 7.7 × 6.5 cm, while the mean dimensions of the flap were 12.1 × 8.3 cm. Time efficient reconstructions with the modified keystone flap were performed without any following major complications. Minor wound dehiscence occurred in only one case, which soon healed with conservative management. Considering its simple design, reliable flap survival, minimal donor-site morbidity, optimal flap thickness, and evenly distributed surgical tension, our novel technique of the modified keystone flap is as an excellent surgical option for the reconstruction of pressure ulcers in the gluteal region.