Emergency department overcrowding is a serious and ongoing issue across Canada. Short stay units (SSUs) have emerged as a potentially useful strategy for managing overcrowding in emergency departments. Members of The Ottawa Hospital senior management team contemplating the introduction of an SSU to help alleviate emergency department overcrowding approached our rapid response service to conduct a rapid review on the safety and effectiveness of SSUs. This paper presents the process for conducting this review, its findings, and the end-user report generated for the senior management team and other stakeholders.