Anterior thoracic spinal instrumentation has traditionally been supported by a posterior thoracic construct spanning from at least two levels above to two levels below; however, instrumentation at a single-level above and below may be adequate to support such a construct. We report two cases of transthoracic corpectomy with short-segment posterior fixation with success in long-term stabilization. Two patients with thoracic vertebral malignancy resulting in spinal deformity and spinal cord compression underwent transthoracic corpectomy with placement of an expandable cage proceeded by posterior fixation one level above and one level below. Using the Cobb angle, the degree of kyphosis was measured at 3, 6, and 12 months postoperatively. Long-term spinal stabilization was achieved in both patients. There was no significant increase in kyphosis and no evidence of hardware failure in either patient during the follow-up period. Transthoracic corpectomy with supplementary posterior fixation one level above and below may be adequate to stabilize the spine.