Nearly all children with femoral anteversion spontaneously remodel by age 8. Femoral derotational osteotomies are performed in older children with persistent excessive femoral anteversion when children or adolescents are limited in activities of daily living or sports. Procedures for correction of the anteversion vary, and no one procedure has been shown to be superior. Since 1997 the authors have corrected idiopathic excessive femoral anteversion thorough a diaphyseal osteotomy with fixation using a rigid intramedullary pediatric femoral nail. The purpose of this study was to describe the technique and results of this new technique. A retrospective study was conducted of all femoral derotational osteotomies performed with a pediatric femoral nail in 13 consecutive patients and 21 affected limbs. All patients complained preoperatively of frequent tripping during sports and activities of daily living. The mean preoperative rotation included internal rotation of 77 degrees and external rotation of 15 degrees. Standing AP radiographs of all patients were obtained at final follow-up. All patients were evaluated clinically and radiographically at a minimum of 1 year after surgery. All patients noted improvement in the ability to participate in activities without tripping. No patient limped at final follow-up. No intraoperative or postoperative complications occurred. Healing of the osteotomy was present at a mean of 6 weeks. All osteotomies healed in anatomic alignment. Mean final hip rotation included internal rotation of 40 degrees and external rotation of 57 degrees. No patient had substantial changes of valgus or femoral neck narrowing at final follow-up. Femoral derotational osteotomy with fixation using a small-diameter rigid intramedullary nail placed through the lateral aspect of the greater trochanter is a safe, accurate, and effective method of correcting excessive femoral anteversion in symptomatic children.