Ischial sores are caused by a synovial bursa that develops from pressure or shear forces acting on the ischial bone. Because of this mechanism, the actual skin defect of ischial sores is often smaller than the subcutaneous pocket. Therefore, ischial ulcers are frequently treated by complete pocket resection and reconstruction with an appropriate flap. As an alternative method, we here describe the treatment of five patients with relapsing ischial sore by the application of platelet-rich plasma (PRP) and direct closure by suturing.Ischial sores are often found on the buttocks of paraplegia patients who are seated in a wheelchair for long periods, and they recur at a high rate in these individuals. Our method is useful because no normal tissues around the IPS are resected, and thus it is still possible to use local flaps if a sore relapses.