The choice between wedge resection and segmentectomy as a sublobar resection method for patients with cT1N0 lung cancer remains debatable. This study aimed to evaluate the clinical outcomes after wedge resection and segmentectomy for patients with cT1N0 lung adenocarcinoma. The study enrolled 1002 consecutive patients with cT1N0 lung adenocarcinoma who underwent sublobar resection at the authors' institution between 2011 and 2017. A propensity score-matching analysis was used to compared the clinical outcomes between the wedge resection and segmentectomy groups. Wedge resection was performed for 810 patients (80.8%), and segmentectomy was performed for 192 patients (19.2%). Wedge resection resulted in better perioperative outcomes than segmentectomy. The multivariate analysis showed that the significant risk factors for poor disease-free survival (DFS) were elevated preoperative serum carcinoembryonic antigen levels, total tumor diameter greater than 2 cm, and a consolidation-to-tumor (C/T) ratio higher than 50%. After propensity-matching, no differences in overall survival or DFS were noted between the two matched groups. However, subgroup analysis showed that segmentectomy was associated with better DFS than wedge resection (p = 0.039) for the patients with a tumor diameter greater than 2 cm and a C/T ratio higher than 50%. Segmentectomy is the appropriate surgical method for sublobar resection in cT1N0 lung adenocarcinoma patients with a tumor diameter greater than 2 cm and a C/T ratio higher than 50%. Wedge resection may be a safe and feasible sublobar resection method for patients with a tumor diameter of 2 cm or smaller or a C/T ratio of 50% or lower.