Objectives: Minimally invasive techniques for lung cancer surgery have revolutionized thoracic surgery, and single-port approaches are becoming increasingly used. We analyzed our experience with uniportal video-assisted thoracoscopic surgery for lobectomy to identify the number of procedures necessary to achieve proficiency according to clinical outcomes., Methods: We queried our institutional prospective database for all single-port lobectomies in patients with early-stage lung cancer performed by a single surgeon from 2014 to 2017; 274 patients met the inclusion criteria. Using cubic splines, we derived 3 distinct learning phases based on the length of the procedure. Blood loss, additional port insertion, and conversion to thoracotomy were also compared according to these learning phases., Results: The initial phase (procedures 1-60) had the longest procedure times and the most variability in procedure length (158.8 ± 52.2 minutes) compared with the transition phase (procedures 61-140; 145.9 ± 43.8 minutes) and the proficient phase (procedures 141-274; 117.9 ± 32.6 minutes, P < .001). Blood loss (156 mL vs 130.4 mL vs 64.9 mL, P = .003), conversion rate to thoracotomy (11.7% vs 3.8% vs 0.7%, P = .001), and need for a second incision (8.3% vs 5% vs 0.7%, P = .025) were all highest during the initial phase. In a multivariable model, there was a significant interaction between procedure number and learning phase (P = .003), indicating that the effect of each additional procedure on procedure length differed in each phase., Conclusions: In this analysis, a distinct learning curve for uniportal video-assisted thoracoscopic surgery lobectomy was observed. Procedure time decreased sharply at approximately the 60th procedure, but 80 additional lobectomies were required to master the approach., (Copyright © 2019 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)