Objective To investigate the operative method and effectiveness of repairing defects at medial malleolus in children with vascularized fibular head composite flap. Methods Between November 2008 and January 2011, 8 children with bone and soft tissue defects at the medial malleolus were treated. There were 5 boys and 3 girls, aged 2-9 years (mean, 4.6 years). Injuries were caused by machine twisting in 2 cases and by wheel twisting in 6 cases. Soft tissue defect area ranged from 3.5 cm × 3.0 cm to 7.0 cm × 4.5 cm; defect was total in all medial malleolus. The disease duration from injury to admission was 2-8 hours (mean, 4.5 hours). Defects were repaired with vascularized fibular head composite flap carrying the skin around the head of the fibula in 5 cases, and with vascularized fibular head composite flap and skin flap above the medial malleolus in 3 cases having too large defect (gt; 5 cm × 4 cm). The donor sites were repaired with direct suture in 2 cases and with skin graft in 6 cases. Results All 8 fibular head composite flaps and 3 skin flaps above the medial malleolus survived completely. Wounds healed by first intention; the skin grafts at donor sites survived in the other cases except 1 case having local necrosis, with healing of incision by first intention. The patients were followed up 10 months to 3 years (mean, 22 months). The color and elasticity of the flaps were good. All the children had equal leg length. Of 8 cases, 6 had no joint valgus; 2 cases had progressive ankle varus after 1 year of operation. The ankle flexion and extension function returned to normal in 5 cases, and was slightly limited in 3 cases; horizontal side, forward and backward movements had no difference compared with normal side. According to American Orthopaedic Foot and Ankle Society (AOFAS) ankle function evaluation criteria, the results were excellent in 5 cases, and good in 3 cases at 10 months after operation. X-ray film showed that the ankle hole gap development of both sides was similar; no premature closure of the epiphysis or bone bridge formation of the medial malleolus was observed in 6 cases, and bone bridge formed in 2 cases after 1 year of operation. Conclusion The satisfactory short-term effectiveness can be obtained in repairing children medial malleolus and soft tissue defects by vascularized fibular head composite flap, and the reconstructed medial malleolus can develop with the growth of children. Long-term effectiveness still need more follow-up study.