Recently, several perforator flaps have been described in the literature. Covering a tissue defect in a limb generally requires a thin flap to provide the reconstructive site with aesthetic and functional refinement in a single stage. The medial sural artery perforator flap presents a new concept that involves a single musculocutaneous perforator to supply a whole skin flap. We used the pedicled medial sural artery perforator flap for coverage of the skin defect around the knee. The patients were 2 men and 3 women who were 36-72 years old. The causes of the skin defect were one by osteomyelitis of the tibia and 4 by infection after total knee arthroplasty. The flaps were 4 × 2 cm - 23 × 5 cm. All flaps survived and infections healed. The donor site was closed in a single stage of no more than 5 cm width. Results show that the pedicled medial sural artery perforator flap is useful for the coverage of skin defects around the knee.