Non-traumatic Altered States of Consciousness (ASC) is a non-specific consequence of various etiologies. Awareness and understanding of the relative frequencies of the various etiologies of ASC can facilitate the development of effective diagnostic and therapeutic approaches to patient management and promote efficient use of our resources in managing these patients. The aim of this study was to collect and present data on the various etiologies of non-traumatic ASC in an ED population. Various risk factors were studied to determine association with 2-week outcome. Data on patient demographics, clinical features, investigations done, treatment given and outcome were collected prospectively over a six month period. Criteria for ASC are GCS scores less than 15; patients not alert or orientated to time, place or person; reduced responsiveness to physical or verbal stimulation; difficulty to arouse; patients unable to remain awake or conversant; confusion, restlessness or agitation; and any other findings suggesting ASC. A description of the findings along with a review of the literature is presented.