Neglected femoral neck fractures in young adults pose a great challenge to orthopedic surgeons because of the high risks of nonunion and osteonecrosis. We attempted to determine whether free vascularised fibular grafting through an anterior approach could enhance bone union, improve hip function and reduce complications in the treatment of such fractures. Thirteen patients with neglected femoral neck fractures were treated with a free vascularised fibular graft through an anterior approach between 2004 and 2008. The mean age was 30.9 years (range, 17-47 years). The average delay between injury and operation was 6.7 months (range, 1.5-22 months). All 13 cases had ununited fractures but without osteonecrosis of the femoral head on plain radiographs before coming under our care. The average follow-up was 51.2 months (range, 36-75 months). All patients had fracture union within an average of 4.8 months (range, 3-9 months). Postoperatively, 9 patients had coxa vara of 10 to 20 degrees and leg discrepancy between 0.5 to 1.5 cm. One patient had coxa vara deformity of 25 degrees and 2-cm leg discrepancy. No patients developed osteonecrosis of the femoral head or donor-site morbidity. The mean Harris hip score improved from 55.5 points preoperatively to 84.8 points postoperatively (p<0.01). This procedure may be useful and safe in the treatment of neglected femoral neck fractures in young adults, but further studies with a large number of patients are needed.