Abstract Background Postoperative hoarseness after general anesthesia is associated with patient discomfort and dissatisfaction. A recent large retrospective study showed that single-lumen endotracheal tube intubation by a trainee did not alter the incidence of postoperative pharyngeal symptoms compared with intubation by a senior anesthesiologist. However, there is limited information about the relationship between the anesthesiologist’s experience and hoarseness after double-lumen endotracheal tube intubation. We tested the hypothesis that double-lumen endotracheal tube intubation performed by a trainee increases the incidence of postoperative hoarseness compared to intubation by a senior anesthesiologist. Methods This retrospective observational study included patients who underwent lung resection between April 2015 and March 2018 at a university hospital. Double-lumen endotracheal tube intubation was carried out with a Macintosh laryngoscope. We divided the patients into 2 groups - one group comprised of patients who were intubated by a trainee anesthesiologist with < 2 years of experience, and the other group comprised of those who underwent intubation by a senior anesthesiologist with ≥2 years of experience. The primary outcome was the incidence of postoperative hoarseness 24 h after surgery and we collected data on postoperative hoarseness using a checklist of postanesthetic adverse events. One-to-one propensity score matching was conducted and P values < 0.05 were considered statistically significant. Results There was a total of 256 eligible patients, of which 153 underwent intubation by trainee anesthesiologists, and the remaining 103 patients were intubated by a senior anesthesiologist. The one-to-one propensity score matching resulted in 96 pairs of patients for the groups. The incidence of postoperative hoarseness 24 h after surgery was significantly higher in patients who were intubated by a trainee anesthesiologist than in patients who were intubated by a senior anesthesiologist (9.4% vs. 2.1%, respectively; P = 0.03). Conclusions Double-lumen endotracheal tube intubation by trainee anesthesiologists with < 2 years of experience increased the incidence of postoperative hoarseness 24 h after surgery compared to intubation by senior anesthesiologists with ≥2 years of experience.