Background of study: Hyponatraemia is a commonly encountered plasma electrolyte abnormality. As aggressive or inappropriate therapy of hyponatraemia can be more harmful than the condition itself, clinicians should be familiar with the diagnosis and management of various forms of hyponatraemia. Objective: To assess the socio-clinical profile of the patients admitted in the Intensive care unit with hyponatraemia __ampersandsignamp; to assess predictors of mortality in the study population Research Methodology: This prospective observational study was done in the Intensive care unit of SSKM Hospital / IPGME__ampersandsignamp;R, Kolkata during April 2011 to March 2012 among the patients having serum sodium level less than135 mmol/l. The data were collected on predesigned questionnaires which include age, gender, clinical findings, complications and laboratory tests. SPSS 16.0 version was used for statistical analysis Results: Males are more commonly affected than females. Chronic liver disease is most common underlying condition associated with hyponatraemia. On multivariate logistic regression analysis serum sodium was found to be statistically significant predictor for mortality (as p value __ampersandsignlt; 0.05). Conclusion: Hyponatraemia could predict the mortality in intensive care unit patients, so proper emphasis should be given to address the situation