Abstract Hyponatremia is the most common, electrolyte abnormality out of all in critically ill neurological patients. TBM is a common cause of sub-acute and chronic meningitis in developing countries like India. It is an important cause of stroke in young individuals in India. Hyponatremia in TBM is multifactorial and may be due to anorexia, nausea, vomiting, poor intake of sodium, diarrhoea, drugs and associated comorbidities. Method: This study was a six-month cross-sectional study of consenting patients admitted with a diagnosis of TBM at our hospital. Patients were labelled as having hyponatremia, SIADH and CSWS as per operational definitions. The findings were noted in the Performa along with other demographic Patients were classified as per BMRC stage I/II/III and duration of symptom