To study the etiological profile of non traumatic coma patients and identify the clinical factors those are predictive of the outcome Prospective observational hospital based study where non traumatic comatose patients of age more than 13 with GCS ≤8 over a period of 12 months were studied. Patients were examined with detailed history, systemic examination and necessary investigations. Initial and 24 hour GCS scores recorded and patients were followed up for 2 weeks to record Glasgow outcome score. Data was analysed using necessary statistical tools Commonest cause for non traumatic coma is cerebrovascular accident followed by metabolic encephalopathy and infections. Total mortality was 58.75% with highest mortality among cerebrovascular accident cases (69.44%). Total duration of coma had significant negative correlation with outcome score(r=-0.2604). Initial and 24 hr GCS score have significant positive correlation with the outcome score. Multivariate regression analysis showed that out of GCS parameters only motor response had significant predictive contribution to outcome. Low GCS≤5, abnormal pupillary response and absent dolls eye response had high positive predictive value for mortality of comatose patients. CVA is the commonest cause of Non traumatic coma in tertiary care centre and it has the worst prognosis among its causes. Prolonged duration of coma, initial and 24 hr GCS score, motor response and brain stem reflexes have high predictive value in the functional outcome of comatose patient.