BACKGROUND Femoral neck lengthening and transfer of the greater trochanter were introduced by Morscher as treatment for patients with coxa breva and overgrowth of the greater trochanter. In this study we evaluated intermediate and long-term results of this operation. METHODS We reviewed clinical and radiographic results of 18 patients (20 hips) who were treated by Morscher osteotomy. Ten patients had Perthes disease, 4 had developmental dysplasia of the hip, and 4 had avascular necrosis of the hip. The median age at surgery was 16 years [interquartile range (IQR): 14 to 17.5]. The median follow-up period was 7 years (IQR: 4.5 to 10). All patients were evaluated clinically by means of Harris Hip Score (HHS) before and after surgery. RESULTS Preoperative clinical examination revealed that all patients had a limp and a positive Trendelenburg test. Median HHS was 72.5 (IQR: 69 to 83). Postoperatively, the Trendelenburg test was negative in 14 hips and positive in 6 hips. Postoperative median HHS was 94.5 (IQR: 89 to 96). Radiographic examination showed progression of osteoarthritis in 3 patients. One operation failed and was converted to total arthroplasty (total hip replacement) after 4 years. Two hips required total hip replacement 10 years after the operation. Leg length discrepancy was reduced in 17/20 hips. Overall patient satisfaction level was good-excellent in 12 patients, fair in 4, and bad in 2 patients. Postoperative complications included blade migration (1 patient (and wire breakage (2 patients). CONCLUSIONS Morscher osteotomy can be effective for the treatment of patients with short femoral neck and overgrowth of the greater trochanter with a positive Trendelenburg test and mild leg length discrepancy. A congruent nonarthritic hip joint is a prerequisite for the success of the operation. METHODS Level IV.