RATIONALE: Despite increasing prevalence rates, anaphylaxis is underdiagnosed and undertreated by physicians, suggesting a gap in medical education. We hypothesized that the early introduction of anaphylaxis education into the medical school curriculum would improve students' knowledge of anaphylaxis diagnosis and management. METHODS: Third-year medical students were studied prospectively during their pediatric clerkship at a children's hospital. Students were randomly assigned to group A (didactic lecture plus simulation laboratory) or group B (didactic lecture only). All students completed a pre-test to assess baseline knowledge of anaphylaxis. All students then received a lecture on anaphylaxis, followed by a post-test. Group A then participated in a scripted anaphylaxis scenario in the Simulation Laboratory. All subjects completed a long-term follow-up test and satisfaction questionnaire 8-12 weeks later. RESULTS: A total of 87 students completed the study. Mean test scores improved significantly for both groups from pre-test (Group A: 5.93 6 1.70, Group B 5.86 6 1.44) to post-test (Group A 9.16 6 1.00, Group B 9.24 6 0.98), p <.01. However, long-term follow-up scores did not differ between Groups A (7.00 6 1.57) and B (6.93 6 1.76), p5.85. Most students reported a positive learning experience (97.8% of Group A and 76.2% of Group B). CONCLUSIONS: Although students strongly support simulation training for anaphylaxis education, the addition of a simulation module to didactic lecture does not improve long-term retention of anaphylaxis knowledge. Future studies should focus on other educational modalities that will enhance medical student knowledge of this potentially fatal condition.