OBJECTIVES: Although simulation is considered integral to general surgery training, its role has only recently been recognized in thoracic surgical education, perhaps due to a lack of widely available, validated simulators for advanced thoracic procedures. This study evaluates the construct, content and face validity of an inexpensive, easily reproducible simulator for teaching thoracoscopic lobectomy. METHODS: Construct validity (ability of the simulator to discriminate between users of different skill levels) was assessed by having surgical trainees perform a lobectomy on the simulator. Participants were divided into three groups (experienced, intermediate and novice) based on self-reported experience with minimally invasive surgery. After instruction and practice time to limit the effect of any simulator-specific learning curve, each performed a left upper lobectomy that was scored using a standardized assessment tool incorporating total time plus weighted penalty minutes assigned for errors. Content validity (simulator requires same steps and decision-making as a clinical lobectomy) was assessed using a Likert scale by those participants who had previously seen a thoracoscopic lobectomy in a patient. RESULTS: Thirty-one residents participated in the study (12 experienced, 6 intermediate and 13 novice). All 12 experienced participants completed the lobectomy. The other groups were less successful with 4 of 6 in the intermediate group and 5 of 13 in the novice group completing the lobectomy (P = 0.004). The mean times for lobectomy + penalty minutes were 35 + 6.8 (experienced), 50 + 13 (intermediate) and 54 + 20 (novice). Differences between groups were statistically significant for experienced vs. novice (P < 0.001) and experienced vs. intermediate (P < 0.04). Content validity was assessed by the 18 participants who had previously seen a thoracoscopic lobectomy with a mean of 9.2 of 10 possible points. CONCLUSIONS: The thoracoscopic lobectomy simulator used in this study demonstrates acceptable validity and can be a useful tool for teaching thoracoscopic lobectomy to trainees or experienced surgeons.