Given the nature of emergency department and urgent care, patients do not typically return to the same clinician for follow-up care, limiting opportunities for direct feedback on diagnostic performance. Many health systems do, however, send follow up surveys after discharge, which presents an opportunity to solicit patient information on diagnostic performance. This article describes the development and psychometric testing of a post-discharge survey, Patient-Report to IMprove Diagnostic Excellence in Emergency Department settings (PRIME-ED). Responses showed high internal consistency in the three domains groups: diagnostic process, accuracy of diagnosis, and communication of diagnosis.