Segmentectomy demands a thorough knowledge of the three-dimensional bronchovascular anatomy of the lung. This anatomic detail makes segmentectomy significantly more challenging than lobectomy. Several principles must be applied when performing segmental lung resection: (1) the surgeon should avoid dissection in a poorly developed fissure, (2) use the transected bronchus as the base of the segmental resection during the division of the lung parenchymal in the intersegmental plane, (3) consider the use of endostapler division of the pulmonary parenchyma to reduce the air leak complications related to "finger fracture" dissection of the intersegmental plane, and (4) consider the use of adjuvant iodine 125 brachytherapy as a means of reducing local recurrence following sublobar resection. Increasing evidence supports the use of anatomic segmentectomy in the treatment of primary lung cancer for appropriately selected patients. This resection approach seems most appropriate in the management of the small (<2 cm in diameter) peripheral stage I NSCLC in which a generous margin of resection can be obtained. Accurate intraoperative nodal staging is important to estimate the relative use of these approaches compared with more aggressive resection and to determine the need for adjuvant systemic therapy if metastatic lymphadenopathy is identified. Future investigations comparing the results of sublobar resection with lobectomy will more clearly define the role of segmentectomy among good-risk patients with clinical stage I NSCLC. At the present time, it seems that sublobar resection is an appropriate therapy for the management of stage I NSCLC identified in the elderly patient, those individuals with significant cardiopulmonary dysfunction, and for the management of peripheral solitary metastatic disease to the lung. Because the primary disadvantage of sublobar resection is that of local recurrence, intraoperative adjuvant iodine 125 brachytherapy may be considered to minimize this local recurrence risk.