PURPOSE: This study evaluated mid-term clinical and radiological results of autologous bone marrow transplantation (BMT) for early stage osteonecrosis of the femoral head (ONFH) and analyzed prognostic factors. MATERIALS AND METHODS: From November 2003 to April 2008, 101 hips of 93 patients with early stage ONFH who underwent autologous BMT were followed for at least five years. For clinical results, preoperative and postoperative Harris hip scores (HHS) were evaluated and survival rate was obtained at the point of performing total hip arthroplasty or femoral head collapse progression. Radiologic results were assessed by changes in necrosis size on magnetic resonance imaging performed preoperative and postoperatively. For evaluation of prognostic factors, survival rate was analyzed according to age, gender, etiology, stage, necrosis size, and location. RESULTS: Averaged HHS at latest follow up showed no significant change in comparison with preoperative HHS. Of 101 hips, 35 hips required arthroplasty and six hips were running head collapse. Groups with use of steroid, lateral location of necrosis, large size of necrosis, or large necrotic angles showed lower survival rate. However, age, gender, and stage had no effect. CONCLUSION: In early days, autologous BMT for early ONFH can be considered as a treatment for improvement of clinical features and delay of radiologic progress. However, after some years, there was no effect compared with the natural course of ONFH.