One hundred and sixty patients had reconstructive surgery of the lower extremity with the microsurgical technique at the department of orthopaedic surgery, Yonsei University College of Medicine from 1982 to 1989. There were ninty-six cases of men and sixty-four cases of women, in which the mean age was 23.8 years. These patients were followed for 21.4 months. The causes were 114 cases from traffic accidents, 18 cases from tumors, 12 cases from machinery injuries, 5 cases from burns, 2 cases from explosive injuries, and 9 cases from other reasons. There were 55 cases of scapular flap, 35 cases of groin flap, 23 cases of free vascularized osteocutaneous flap, 18 cases of parascapular flap, 9 cases of combined scapular and latissimus dorsi flaps, and 8 cases of segmental resection and rotationplasty. Success in reconstructive surgery with the microsurgical technique was achieved in one hundred and thirty four cases, and function and cosmetic results were excellent. Free vascularized flap with development of the microsurgical technique has taken an important role in reconstruction of large extremity defects where skin graft and distant flap were not applicable. Reconstruction of the lower extremity with the microsurgical technique is indicated with free vascularized osteocutaneous flap when there is a large defect of bone, a need for injured nerve replacement, and in the case of needed multiple staged operations. In these instences, this technique is regarded as simple one-staged reconstructive surgery.