Hyponatremia is the most commonly encountered electrolyte abnormality in a hospital setting. Recent studies on hyponatremia have been limited to the patients with severe hyponatremia and there has been no consensus on optimal management of hyponatremia. High mortality among the patients of hyponatremia is secondary to the underlying medical condition, rather than the degree of hyponatremia. This study was conducted at Medical Intensive Care Unit at D Y Patil University School of Medicine Hospital, Mumbai of 100 patients. Successive patients of hyponatremia who were admitted to the Intensive Care Unit in the hospital were included in the study. These patients were evaluated for the underlying cause of hyponatremia, which included detailed history and physical examination followed by appropriate laboratory investigations based on the serum osmolality. Patients were followed up till the hyponatremia was corrected or patients were discharged from the hospital.