The authors reviewed the occurrence in their emergency department of cases of serious neurologic problems initially thought to be conversion disorders or similar psychogenic conditions. Their aim is to indicate the significance of this issue for emergency physicians (EPs) because of its contribution to the incidence of medical errors. Although there are no national statistics, the authors estimate by extrapolation that thousands of such cases probably have occurred and large numbers may still occur each year in the United States, sometimes resulting in patient injury. They have identified ways of anticipating and attempting to prevent such occurrences. Proposed interventions focus on education regarding the difficulty of diagnosis, patient-based risk factors, and physician-based attitudes and thought processes. The authors also include suggestions for systemic "safety nets" that will help to ensure quality of care, such as appropriate imaging and consultation. Review of texts and journals readily accessible to EPs revealed little attention to this subject.