The general treatment methods of chronic osteomyelitis of calcaneus with soft tissue defect was curettage of necrotic bone with antibiotics mixed bone cement insertion or cancellous bone grafting, and free or pedicled flap coverage. The muscle flap for soft tissue defect has many advantages including control of infection, but in cases of pedicled flap in calcaneus, there are some limitations because of functional loss of the donor site, limitation of pedicled length of donor muscle In these reason, free muscle flap was more preferred for pedicled muscle flap. But, in case of small sized defect which was located in center or lateral side of calcaneus, the abductor digiti minimi muscle flap can be one of the solutions. The abductor digiti minimi muscle flap has minimal functional loss of donor site and can be performed easily. There are some reports of the abductor digiti minimi muscle flap in other country, but in korea, this report is the first case report of the abductor digiti minimi muscle flap. We performed one case of abductor digiti minimi muscle flap as a treatment of chronic osteomyelitis of calcaneus and could obtain a good result.