OBJECTIVE: Although lobectomy is the standard surgical procedure for small-sized non-small cell lung cancer (NSCLC), segmentectomy has been performed for various reasons. The aim of this study was to investigate the characteristics of and risk factors for recurrence in early-stage NSCLC patients undergoing segmentectomy. METHODS: We retrospectively reviewed 179 patients with clinical stage I NSCLC who underwent segmentectomy. Preoperative factors were analyzed using the log-rank test for univariate analyses. Multivariate analyses were performed using a Cox proportional hazards regression model to identify independent risk factors for recurrence. For the significant factors, optimal cutoff points were determined by receiver operating characteristic (ROC) analysis. RESULTS: During the follow-up period of 51 months, 18 patients developed recurrence; 5 had locoregional (including 2 with margin recurrences only), 9 had distant, and 4 had both locoregional and distant recurrence. Multivariate and ROC analysis identified radiologic solid tumor size with a cutoff point of 1.5 cm as an independent risk factor for recurrence. Three patients in the solid size < 1.5 cm group (n = 119) developed recurrence, 2 of whom had surgical margin recurrence, compared to 15 patients in the solid size ≥ 1.5 cm group (n = 60). CONCLUSIONS: The indication for segmentectomy should be decided upon with caution, and the segments to be resected should be carefully considered to secure an appropriate surgical margin in this low-risk subgroup of patients because they may have a relatively higher risk of surgical margin recurrence, despite being at decreased risk.