Background: Pediatric intraoperative emergencies are rare but it is crucial for an anesthesia resident to be proficient in their management. Even the more common emergencies like anaphylaxis may not happen frequently for this proficiency to occur. Simulation increases exposure to these rare events in a safe learning environment to improve skills and build confidence while standardizing curriculum. Objective: Anesthesia residents participated in a simulated case of intraoperative pediatric anaphylaxis to evaluate knowledge and performance gaps. The study also sought to determine whether a difference exists between second- (CA2) and third-year (CA3) anesthesia residents when managing pediatric anaphylaxis and cardiopulmonary arrest. Methods: Anesthesia residents completed a standardized programmed simulation of intraoperative anaphylaxis in a 5-year old undergoing tonsillectomy and adenoidectomy. Anaphylaxis presented and progressed to bradycardia and pulseless electrical activity if anaphylaxis went unnoticed or untreated. Key time points were recorded. A scripted debriefing and written evaluation followed. Results: Average time to diagnose anaphylaxis was 7.6 min, and time to give epinephrine was 6.5 min. Thirty-five percent of residents started epinephrine infusion following initial bolus. Average time calling for help between CA3 and CA2 residents was 2.5 min vs 5 min (P = 0.01). CA3 residents verbalized a broader differential, including malignant hyperthermia and pneumothorax. Progression to pulseless electrical activity occurred in 65% of sessions prior to epinephrine being administered. No resident initiated chest compressions for bradycardia. Conclusions: Important performance deficits were seen in senior anesthesia residents during a simulated case of pediatric intraoperative anaphylaxis. Although CA3 performed better, deficits still existed. Anesthesia residents and training programs should partner in developing additional training recognizing anaphylaxis, pulseless electrical activity, and indication for chest compressions in a child.