In 1995, Ginsberg et al. compared lobectomy with limited resection including segmentectomy and wide-wedge resection for stage I lung cancer in a randomized controlled trial and found that limited resection should not be applied to otherwise healthy patients with clinical stage IA lung cancer who can tolerate lobectomy. However, recent advances in diagnostic technology have improved the precision of detecting early-stage and small lung cancers. Therefore, whether radical segmentectomy, anatomical segmentectomy with hilar and mediastinal lymph node dissection (that is more valuable than wedge resection in terms of oncological aspects) and lobectomy are comparable in terms of curative intent for patients with early-stage non-small cell lung cancer (NSCLC) remains controversial. The role of segmentectomy differs according to tumor or patient characteristics. High resolution computed tomography findings of tumor size, location, and the presence or ratio of a ground glass opacity (GGO) component and the maximum of standardized uptake value on fluorine-18-2-deoxy-D-glucose positron emission tomography are important for selecting surgical procedures because the malignant potential of even early-stage NSCLC is variable. The ongoing JCOG0802/WJOG4607L, JCOG1211, and CALGB140503 trials will disclose the influence of segmentectomy for patients with early-staged NSCLCs that are small peripheral tumors based on preoperative high-resolution computed tomography findings about preserved pulmonary function and long-term prognosis. Segmentectomy is a key surgical procedure that general thoracic surgeons will need to master considering that it can be converted to lobectomy if the surgical margin is insufficient or lymph node metastasis is intraoperatively confirmed.