Object ive To inves t igate the operat ive method and cl inical ef fect of repai r ing and reconstructing the traumatic defect of medial malleolus in children with complex tissue flap of vascularized fibular head epiphysis. Methods From July 2003 to December 2007, 8 children with defect of medial malleolus due to wheel injury were treated, including 5 boys and 3 girls aged 2-10 years old. The medial malleolus were completely defected (5 cases at left foot and 3 cases at right foot) and combined with the skin defect around the medial malleolus (4.0 cm × 2.0 cm - 9.5 cm × 5.5 cm). The time from injury to hospital admission was 6-8 hours in 2 cases, and 24-168 hours in 6 cases. The complex of vascularized fibularhead epiphysis and tissue flap was adopted to repair the defect. The flap 4.5 cm × 2.5 cm - 10.0 cm × 6.0 cm in size and the fibular head epiphysis 2.5-3.0 cm in length were harvested. The donor site was sutured directly. Results All wounds healed by first intention, all the composite tissue flap survived with good blood circulation, all the epiphysis of medial malleolus healed within 6-9 weeks, and all the donor sites healed well. All the child patients were followed up for 1-5 year. The color and elasticity of the flaps were good, without cicatricial contracture. The patients had no inversion of ankle joint, with satisfying loading and walking function. Six cases had normal flexion and extension of the ankle and 2 cases were l imited sl ightly (dorsiflexion 10-20°, plantarflexion 35°). Talus has no inner move and ankle joint had no eversion. Seven cases were graded as excellent and 1 as good according to the standard of American Orthopaedic Foot amp; Ankle Society. For the medial malleolus, no premature closure of epiphysis occurred, and the center of ossification grew gradually and well developed l ike the contralateral side. The donor knee joint had normal flexion and extension function, without inversion and instabil ity. Conclusion The complex of vascularized fibular head epiphysis and tissue flap can repair the epiphysis and soft tissue defect of medial malleolus in children at one stage, and the reconstructed medial malleolus can develop with the growth of children. It is a satisfactory method of reconstructing the traumatic defect of medial malleolus in children.