This report describes the case of a 44-year-old woman presenting to a Sleep and Alertness clinic with symptoms of narcolepsy. The patient had clinical and polysomnographic features of narcolepsy, which disappeared after disclosure of severe psychological stress. Following a discussion of the differential diagnosis of narcolepsy, alternative diagnoses are considered. The authors suggest that the patient had a hysterical conversion disorder, or "pseudo-narcolepsy." Careful inquiry into psychological factors in unusual cases of narcolepsy may be warranted.