Objective To assess the clinical efficacy of fibular osteotomy with autogenous iliac bone graft for treatment of nonunion of the tibia. Methods A cohort of 45 patients with postoperative nonunion of tibia between Jul. 2008 and Jun. 2013 were treated by fibular osteotomy combined with autogenous iliac bone graft in Changhai Hospital of Second Military Medical University. According to anatomical classification, there were 29 cases of hypertrophic nonunion, 17 cases of atrophic nonunion and two cases of pseudoarthrosis. For primary fixation, 32 cases had plates internal fixation, 11 had intramedullary nail and two had external fixation. Eight patients with stable plate internal fixation were treated by fibular osteotomy with autogenous iliac bone graft, 35 patients with failed internal fixation and two patients with failed external fixation were treated by removing implant and exchanging compression plate with fibular osteotomy using autogenous iliac bone graft. The status of fracture healing and relative complications were assessed by lateral and frontal X-ray. Functional recovery of the ankle was evaluated by Olerud-Molander Ankle Score (OMAS). Results The operation time was 1.3-2.5 (1.7±0.5) h, the intra-operation blood loss volume was 200-500 (250.0±59.6) mL, the fibular osteotomy length was 2-3 (2.4±0.5) cm, and the volume of iliac grafting was 3-23 (7.8±1.3) cm³. The follow-up time was 12-48 (16.5±3.3) months and the fraction healing time was 3-11 (5.6±2.4) months. The healing of 26(58%) patients took 3-5 months, 13(29%) patients took 6-8 months and 6(13%) patients took 9-11 months. Twenty-seven patients had no limb shortening, nine patients had limb shortening of <1 cm, six patients had limb shortening of 1-2 cm and three patients had limb shortening of >2 cm. The function of lower limb joints was excellent in 23 cases, good in 14 cases, common in 5 cases and bad in 3 cases at last follow-up. Conclusion The fibular osteotomy with autogenous iliac bone graft can create pressure on the broken bone end and increase the broken bone end contact area, promoting fracture healing and reducing complications.