BACKGROUND In patients undergoing limb-salvage internal hemipelvectomy, pelvic ring reconstruction is mandatory to maintain the stability of the pelvis and the spinal column, which finally expected to achieve a good functional outcome. However, no optimal reconstruction method has been established. In addition, no previous reports have highlighted the long-term complications of pelvic ring reconstruction after internal hemipelvectomy. We aimed to analyze the outcome of pelvic ring reconstruction using a double-barreled free vascularized fibula graft (VFG) after internal hemipelvectomy with special reference to long-term complications. METHODS We conducted a retrospective review of 9 consecutive patients (5 male, 4 female; mean age 31 years) who underwent pelvic ring reconstruction using a double-barreled free VFG after internal hemipelvectomy (P1, n = 4; P1 + 4, n = 3; P1 + 2, n = 2) at our institution between 1998 and 2013. The mean follow-up period was 55 months (range 3-131 months). RESULTS The mean length of the bone defect was 9 cm. The methods of fixation included a Cotrel-Dubosset rod (n = 4), screw (n = 3), and screw and plate (n = 2). Bone union was achieved in 5 of 8 patients (63 %) over a 1-year follow-up. The mean period required for bone union was 5.4 months (range 3-7 months). There were 3 early postoperative complications: 2 deep infections resulting in graft removal and 1 implant failure resulting in non-union. Among 3 patients, 2 developed scoliosis within 5 years. One patient developed lumbar disc hernia as a result of scoliosis, for which surgical intervention was required. The mean Musculoskeletal Tumor Society score was 57 % at the last follow-up. CONCLUSIONS In conclusion, this reconstruction method can achieve an early and high rate of bone union and provide good functional outcome. However, follow-up with careful attention to postoperative complications, including deep infection in the early postoperative period and spinal deformity in the long term, is necessary.