Six patients underwent wrist arthrodesis using vascularized fibular grafting for treatment of a segmental bone defect across the wrist. Five patients had defects resulting from excision of a giant cell tumor at the distal radius, and one patient had a defect after debridement of a chronic infection. In all cases, bone union was achieved within 3 to 6 months after vascularized fibular grafting without additional procedures. Measurement of postoperative roentgenograms revealed that the average of fixed wrist angle was 13 degrees extension. Postoperatively, average grip strength on the affected side was 59% of that on the unaffected side, and the average range of forearm rotation was 123 degrees. The mean Enneking functional score was 84% at a mean follow-up period of 64 months. There was no recurrence of a tumor or infection. Wrist arthrodesis using vascularized fibular grafting is a useful procedure for the treatment of a segmental bone defect across the wrist.