A university teaching hospital in Karachi, Pakistan.To define the clinical characteristics and outcome of miliary tuberculosis (TB) patients from a low human immunodeficiency virus (HIV) prevalence country.Review of adult miliary TB patients admitted between 1994 and 2001. Clinical characteristics of those dying from miliary TB were compared with those of the survivors.Most of the 110 cases reviewed were middle aged or elderly, with a female preponderance. An underlying medical condition was present in 47%. Presenting symptoms were of several weeks' duration, and mostly constitutional (fever and weight loss). Common laboratory findings included anaemia (62%), lymphopaenia (71%), hyponatraemia (74%), elevated serum alkaline phosphatase (57%) and hypoalbuminaemia (92%). Typical miliary pattern was observed in 77% of radiographs. Sputum smear and culture were positive in respectively 36% and 52% of those tested. Biopsy was performed in selected patients. Mean hospital stay was 8.8 days, and mortality was 30%. Those who died were significantly older than survivors and had a more fulminant course. Presence of altered mental status, lung crackles, leucocytosis, thrombocytopaenia and the need for ventilation were associated with increased mortality.Miliary TB carries a high mortality. It should be considered in patients who present with prolonged systemic symptoms. A positive TB culture or biopsy is needed to establish a diagnosis.