Background: Hyponatremia is one of the common electrolyte abnormalities in hospitalized patients. The spectrum of different etiologies of hyponatremia have both prognostic and therapeutic implications. Aims and Objectives: To evaluate the clinical and etiological profile of hyponatremia, and to study the outcome of hyponatremia. Study Design: A prospective cohort Study. Materials and Methods: A total of 100 consecutive patients with hyponatremia over a period of one year were enrolled. Detailed clinical history, physical examination, baseline biochemical and metabolic profile followed by serum and urine osmolality and urine sodium was done in all patients. Results:Out of 100 consecutive patients enrolled in this study, thirtyeight were males and sixty-two were females with male to female ratio of 1:1.6, with mean age of 61.2 years. Commonest neurological complaints were confusion (46%), lethargy (20%) and seizures (10%). Diuretic use was the most common cause of hyponatremia 34%, followed by SIADH 29%, gastrointestinal losses 10% and chronic kidney disease in 8% of patients. Chronic liver disease and chronic heart failure contributed 6% each. Other rare causes like hypothyroidism, primary adrenal failure, primary polydipsia and Beer potomania was found in 7% of patients. 46% patients were euvolemic, 37% hypervolemic and 17% hypovolemic. Conclusion: Diuretics are the most common cause of hyponatremia followed by SIADH and gastrointestinal losses. Mortality rate in our study was 12%, with maximum mortality(50%) in SIADH group .