The results of anterior and posterior excision or wedge resection of a hemivertebra and arthrodesis of the spine were reviewed retrospectively for thirty-seven patients. The degree of correction that was obtained and maintained, the balance and alignment of the trunk, changes in pelvic obliquity, and associated complications were evaluated. The average age at the time of the operation was twelve years (range, six months to forty-two years). The average duration of follow-up was six years (range, two to nineteen years). The resection was at the mid-thoracic level in six patients, at the thoracolumbar level in nine, at the mid-lumbar level in seven, and at the lumbosacral level in seventeen. (Two patients had an excision of a hemivertebra at two levels.) Instrumentation was used in twenty-eight patients. Postoperatively, all patients were managed with a body cast, with a unilateral or bilateral pantaloon extension, for four to six months. The instrumentation allowed early walking and the use of a unilateral rather than a bilateral pantaloon extension. The index curve (the curve containing the hemivertebra) averaged 54 degrees (range, 18 to 132 degrees) preoperatively, 33 degrees (range, 0 to 105 degrees) postoperatively, and 35 degrees (range, 0 to 110 degrees) at the most recent follow-up evaluation. A measurable improvement in balance was achieved and maintained in nineteen patients. Pelvic obliquity did not change appreciably, as it was related primarily to limb-length inequality in this series. Complications included a temporary nerve-root lesion in seven patients, a permanent neurological deficit involving the first sacral nerve root in one patient, a pseudarthrosis in three patients, and a wound infection in three patients. Six patients had extension of the arthrodesis to include additional vertebrae.