Background:
The annual risk of tuberculosis (TB) in Iran is about 0.5% with annual incidence rate of 23/100000 (16322 cases). Different factors have been postulated as TB predisposing factors. Several studies have linked smoking with pulmonary tuberculosis as the TB incidence in their adult men was 2.4 times higher than women. In Iran, however, this ratio is equal and somewhere the ratio in women is greater. We decided to carry out a case control study in order to evaluate the effect of cigarette smoking on pulmonary TB.