In order to ascertain the role of TNF-alpha in pulmonary tuberculosis, we determined the TNF-alpha productivity of alveolar macrophages(AMs) obtained by bronchoalveolar lavage(BAL), along with the level of TNF-alpha in the serum of patients with tuberculosis including pulmonary, miliary, and endobronchial tuberculosis, healthy controls, and pulmonary diseases such as diffuse interstitial lung disease (DILD) and pneumonia. AMs from patients with pulmonary tuberculosis did not produce a larger amount of TNF-alpha than did those from the healthy control subjects. However, among the patients with pulmonary tuberculosis, the AMs from the fresh and reactivated groups produced a larger amount of TNF-alpha than those from the inactive group. AMs from patients showing positivity in culture produced a larger amount of TNF-alpha than those showing negativity. The average level of serum TNF-alpha in patients with pulmonary tuberculosis was slightly higher than that of the healthy control group. Among patients with pulmonary tuberculosis, significantly increased levels of serum TNF-alpha were noted in the reactivated group compared to those of the fresh and inactive group. Patients with moderate to far-advanced infiltration on their chest X-rays, showed a significantly higher level of serum TNF-alpha than those with minimal involvement on the chest X-ray. Smokers from the healthy control group showed a significantly higher level of serum TNF-alpha than non-smokers from the same group. These results suggest that an increase in the production of TNF-alpha may correspond with the severity of pulmonary tuberculosis.