PEM (Pediatric Emergency Medicine) SIM (Simulation) Cases was developed as a simulation curriculum for the Pediatric Emergency Medicine fellowship program at the NYU Grossman School of Medicine. These cases have also been used with faculty, pediatric and emergency medicine residents and pediatric clerkship students in both our simulation center and in situ in our pediatric emergency departments at Bellevue Hospital Center and the Kids of NYU Emergency Department. The cases cover both common and rare scenarios focusing on essential diagnostic and management of the critically ill or injury child as well as leadership and team communication skills.