A case of miliary tuberculosis, tuberculous meningitis and severe hyponatremia, in a 19 year old man from Pakistan, is presented. The patient was admitted comatose to the ICU. A CT scan of the brain revealed a communicating hydrocephalus and external ventricular drainage was performed. Hydrocephalus is a common complication of tuberculous meningitis, and may be even fatal if left untreated. External ventricular drainage has both therapeutic and predicting value for the benefit of shunt surgery. Prompt ventriculoperitoneal shunting improves outcome, particularly in those patients who present with minimal neurological deficit. Neurological deterioration occurring in a patient under treatment for tuberculous meningitis may have various causes and always requires urgent radiological assessment. Pneumon 2003, 16(1):74-79.