A case of pelvic ring reconstruction with a vascularized pedicle iliac bone graft for removal of a huge sacral schwannoma is reported. It is necessary to reconstruct a pelvic ring when its integrity is impaired. Spinal instrumentation is essential for a temporary stability of the pelvic ring in the course of complete healing, which at times results in instrumentation failure. Several cases of pelvic ring reconstruction using vascularized fibular bone grafts have also indicated positive results attributable to their good blood circulation, but techniques with them are relatively complicated. We applied a vascularized pedicle iliac bone graft to the pelvic ring reconstruction after resection of a huge sacral schwannoma. When a stable pelvic ring was regained by using a lumbosacral instrumentation technique, a tricortical iliac bone graft with its vascular pedicle was harvested, transported into the dead space, and tied to the right residual sacrum and the left ilium. The vascularized graft healed rapidly, and continuity of the pelvic ring was regained. This method is effective for pelvic ring reconstruction in that it does not require microvascular techniques and rapid bone healing can be obtained.