BACKGROUND Hyponatremia is defined as a serum sodium concentration less than 135 mmol/L and is the most common electrolyte disorder encountered in clinical practice. MATERIALS AND METHODS This was a retrospective, descriptive and data analysis study conducted over period of 12 month at a tertiary care centre, to study the clinical profile, aetiology, classification and outcome of hyponatremia. A total 115 consecutive cases who had serum sodium levels of <135 mmol/L were enrolled. The mean and standard deviation and percentage for numerical variables were calculated. Chi square test was used to analyse categorical variables. RESULTS Of a total of 115 patients, 73 (63.47%) were male and 42 (36.52%) were females. There was a predominance of Na + levels of 115-134 mmol/L (mild hyponatremia) 59.13% ['p'< 0.001]. The majority of patients (42.61%) had nausea and/or vomiting ('p'<0.001) and confusion, seizures and coma were associated with moderate to profound hyponatremia ('p' <0.01). The SIADH (37.39%) was the commonest pathophysiological process observed in the present study ['p' <0.0001]. Overall mortality was 9.57%. The patients with Sr. Na + <105 mmol/L had (36.84%) significant mortality compared to >105 mmol/L ['p' <0.002196]. The duration of hospital stay was inversely related to Sr. sodium level. CONCLUSION In present cohort of hyponatremia the SIADH was the commonest aetiology. Confusion, seizures and coma were associated with moderate to profound hyponatremia. The duration of hospital stay was inversely related to serum sodium level with overall mortality of 9.57% which was correlated with severity of hyponatremia.