This study was undertaken to determine the educational benefits of mannequin simulation for performance of tube thoracostomy in a porcine model by medical students. Thirty medical students were randomized into two groups; the first performed tube thoracostomy on a mannequin simulator and then a porcine model; the second used only the porcine model. Performance measures included completion of subtasks, time to perform the procedure, a global score assigned by faculty raters, and a self-evaluation survey. Subtask completion rate was similar in both groups (P > 0.05). Mean time to perform the procedure was 9.8 minutes (+/- 0.9, simulator), and 9.3 minutes (+/- 1.0, nonsimulator, P > 0.05). Global scores were 12.3 (+/- 1.3, simulator) and 11.0 (+/- 1.4, non-simulator, P > 0.05). Self-evaluation of confidence (1 = "very", 7 = "not at all") showed the simulator group was significantly more confident (3.4 +/- 0.42) than the nonsimulator group (4.7 +/- 0.49, P < 0.05). All students met basic competencies to perform tube thoracostomy. The simulator group felt significantly more confident to subsequently perform the procedure on a patient, whereas performance was not statistically significantly different for the two groups. Further trials may be needed to delineate the optimal role for these simulators in teaching tube thoracostomy.