A missed or delayed diagnosis of stroke places patients at risk of permanent disability or death. This article describes how interdisciplinary teams used a failure modes, effects, and criticality analysis (FMECA) to create an acute stroke diagnostic process map, identify failures, and highlight existing safeguards. The FMECA process identified several steps in the diagnostic process as the most critical failures to address, including failure to screen patients for stroke soon after presentation to the Emergency Department (ED), failure to obtain an accurate history, and failure to consider a stroke diagnosis during triage.