We present the discovery of a single-stage use of vascularised sartorius tendocutaneous flap in reconstructing a traumatic hand tendon defect or Achilles tendon in a paediatric case. It is based on the perforators from descending genicular artery, saphenous artery and its venous drainage is by the accompanying vena comitans and long saphenous vein. This flap is reliable: it provides good skin coverage; a vascularised tendon graft with good function achieved and a less obvious scar at the donor site. This is a potential flap for hand and lower leg reconstruction in children with open tendon and Achilles tendon defects respectively.