In situ simulation, simulation that is physically integrated into the clinical environment, provides a method to improve reliability and safety in high-risk areas. Deliberate practice and integration of teamwork skills in the time-pressured clinical environment provides great realism and is a rich resource to identify latent threats and system issues that can compromise patient safety. However, powerful cultural and logistic challenges impede implementation of this practice. Issues related to culture, performance anxiety, time pressures, and patient perceptions that can interfere with successful implementation of in situ simulation are explored. The experiences and lessons learned during implementation of three pilot in situ programs are reviewed. Qualitative data, including feedback from health care providers and patients on the value and concerns related to this practice, are presented. Lessons learned provide guidance that is intended to increase the future success and implementation of in situ simulation.