Twenty-six cases of miliary tuberculosis were studied in retrospect. The mean age of the patients was 62 years. Eighteen patients suffered from another underlying chronic disease. Nine had been treated with corticosteroids or cytotoxic agents. A limited manifestation of tuberculosis had been previously verified or suspected in ten cases. Fever was present in 85% of the patients, frequently combined with fatigue or abdominal pain. Serum alkaline phosphatase was elevated in 81% of the cases. Minor haematological abnormalities (anaemia, etc.) were found in 16 cases and pancytopenia, stimulated lymphocytes or chronic myeloid leucaemia in six. Miliary mottling was found in the chest radiographs of 13 patients. Other findings were pleural effusion, mediastinal node enlargement, opacities suggesting pneumonia or old, possibly tuberculous lesions. Antituberculosis therapy was initiated in 12 patients, two of whom died within a few days. There was a high frequency of liver or system involvements. It is concluded that laparoscopy or liver needle biopsy are valuable diagnostic procedures in patients with fever and elevated alkaline phosphatases of unknown aetiology. A therapeutic test with antituberculous drugs should be undertaken in suspected cases.