To evaluate outcomes of patients undergoing lung segmentectomy using open thoracotomy, Video-Assisted Thoracoscopic Surgery (VATS), or Robotic-Assisted Thoracoscopic Surgery (RATS) approaches. A total of 157 patients (mean age: 68.7 years; 58% male) who underwent lung segmentectomy from 2015 to 2024 at the Thoracic Surgery of Siena were retrospectively enrolled and divided into groups based on the surgical approach: thoracotomy ( = 60), VATS ( = 58), and RATS ( = 39). No significant differences were observed between groups in terms of age, gender, or tumor stage. Peri-operative outcomes, and, in patients with non-small cell lung cancer (NSCLC, = 104), long-term outcomes, were analyzed. Group comparisons were conducted using Kruskal-Wallis, Dunn's test, Chi-squared, or Fisher's exact test and Kaplan-Meier analysis with log-rank test. Conversion rate was 13% and 0% for VATS and RATS, respectively ( = 0.005). Pleural effusion on first post-operative day was lower in RATS than VATS ( = 0.0006) and open ( < 0.0001). The maximum Visual Analogue Scale (VAS) value recorded was lower in RATS than open ( = 0.016) and VATS ( = 0.013). Surgery time was longer for RATS than open ( = 0.001) and VATS ( = 0.013). No differences were found in hospital stay and post-operative complications. In patients with NSCLC, the median follow-up was 25 months. The 90-day mortality rate was 9.5% in thoracotomy, 0% in VATS and RATS ( = 0.05). The 1- and 2-year overall survival was higher in VATS and RATS groups than thoracotomy ( = 0.001 and = 0.040, respectively). The number of harvested lymph nodes was larger in the open group ( = 0.010), while a higher number of stations were harvested in RATS and open than VATS ( = 0.001). No differences were found in local recurrence (= 0.08). RATS segmentectomy ensures a lower conversion rate, less post-operative pain, reduced daily pleural effusion, and a greater number of harvested lymph node stations compared to VATS, providing comparable peri-operative outcomes. RATS and VATS segmentectomy offer an advantage over the open approach in short- and long-term survival.