BACKGROUND: Chest tube insertions (CTI) have a high complication rate, warranting a dedicated Simulation-Based Mastery Learning (SBML) curriculum to acquire technical skills. This randomized controlled trial compares residents' skills in CTI after completing a SBML curriculum with those enrolled in a traditional residency program. METHODS: Junior residents were baseline tested on cognitive and technical skills (Thiel bodies) before randomization into an intervention and control group. The former deliberately trained CTI on a porcine rib model until passing a predefined pass/fail score and were then summatively tested on Thiel bodies. The latter had no additional training opportunities and was evaluated 3 months later. RESULTS: Seventeen residents were recruited and randomized. Following the per-protocol principle, a significant interaction effect for Group × Procedure (F(1,14) = 6.2, p = 0.026) was observed. Between baseline and summative assessment, both the control group (28.0 ± 8.2 vs. 43.6 ± 8.1, p <
0.002) and the intervention group (33.2 ± 7.7 vs. 57.6 ± 5.7, p <
0.002) significantly increased their scores. The intervention group outperformed the control group at summative assessment (43.6 ± 8.1 vs. 57.6 ± 5.7, p <
0.002). All participants in the intervention group and one resident in the control group achieved the pass/fail score. CONCLUSION: This SBML curriculum enabled quicker and superior skill acquisition. Skills trained on a porcine model are transferred to the highly realistic Thiel bodies and reach expert level, potentially increasing resident skill in clinical practice.