Effective teamwork is essential in high-risk healthcare delivery environments. In this study, we aimed to identify facilitators of and barriers to successful teamwork during resuscitations in the NICU Study Design: 36 in-situ interprofessional simulation sessions were held in a level 4 NICU. Each session was followed by a debriefing where staff talked about the simulation scenario but also about their prior experiences during resuscitations in the NICU. Using content analysis, we analyzed the transcriptions of debriefings to address the study aims. Participant responses yielded three major themes: communicating well, getting tasks done well, and working well together. Each main theme had subthemes. Teamwork is a complex process that is enhanced and hindered by a variety of factors. The factors identified in this study can be used to enhance relationship-based teamwork training programs. Future research is needed to determine which teamwork behaviors are most associated with patient outcomes.