OBJECTIVE: True pediatric emergencies are rare. Because resident work hours are restricted and national attention turns toward patient safety, teaching methods to improve physician performance and patient care are vital. We hypothesize that a critical-care simulation course will improve resident confidence and performance in critical-care situations. INTERVENTIONS: We developed a monthly pediatric intensive care unit simulation course for second-year pediatric residents that consisted of weekly 1-hour sessions during both of the residents' month-long pediatric intensive care unit rotations. All scenarios used high-fidelity pediatric simulators and immediate videotape-assisted debriefing sessions. In addition, simulated intraosseous line insertion and endotracheal intubations were also performed. RESULTS: All residents improved their comfort level and confidence in performing individual key resuscitation tasks. The largest improvements were seen with their perceived ability to intubate children and place intraosseous lines. Both of these skills improved from baseline and compared to third-year-resident controls who had pediatric intensive care unit rotations but no simulations (P = .05 and P = .07, respectively). Videotape reviews showed only 54% ± 12% of skills from a scenario checklist performed correctly. CONCLUSIONS: Our simulation-based pediatric intensive care unit training course improves second-year pediatric residents' comfort level but not performance during codes, as well as their perceived intubation and intraosseous ability. Videotape reviews show discordance between objective performance and self-assessment. Further work is necessary to elucidate the reasons for this difference as well as the appropriate role for simulation in the new graduate medical education climate, and to create new teaching modalities to improve resident performance.