Athletic patients with osteonecrosis of the femoral head have few desirable therapeutic options that preserve athletic ability. Because these patients are usually young and healthy, any procedure that avoids total hip arthroplasty would be most desirable. This study prospectively evaluated 15 patients (19 hips) who presented with an average age of 28.5 (range, 12 to 46) years and stages 2 (6/19), 3 (2/19), 4 (9/19), and 5 (2/19) of osteonecrosis of the femoral head. All patients were treated with free vascularized fibular autografting (FVFG) to the femoral head. Postoperative evaluations of pain symptoms and functional activity showed improvements in all patients. The average follow-up time was 8 years. Harris hip scores significantly increased from an average preoperative score of 75.3 to an average postoperative score of 94.8. Seventy-five percent of patients were able to return to their sport after recovery and all patients reported being satisfied with the procedure and would repeat their decision to have surgery. Three patients' hips were converted to arthroplasty at 3, 11, and 17 years post-FVFG. The results demonstrate that FVFG is a successful therapeutic treatment in athletes with osteonecrosis of the femoral head. It reduces pain, increases activity, and allows most patients to return to their sport, an achievement often not possible with other treatment options.