The aim of the present study was to investigate the epidemiological, clinical, laboratory and radiological features of patients with active pulmonary tuberculosis (TB) (with or without pleural involvement) or with pleural TB (in the absence of radiological parenchymal disease). A systematic predetermined form, including 60 items regarding the above-mentioned features, was completed for 5,480 patients. Sputum smear and culture data, radiological findings, and additional extrapulmonary involvement were evaluated in the patients with pulmonary TB (n = 5,094). Epidemiological features, and other clinical and laboratory characteristics were investigated in all patients (n = 5,480). TB was more common among persons aged 20-39 yrs, males, and those living in large urban centres in our region. There were 4,268 newly detected patients (78%), and 1,212 active ex-patients (22%) who had history of previous antituberculosis treatment. Additional extrapulmonary involvement was found in 455 patients (9%). Sputum samples were smear-positive in 3,916 (79%), and culture-positive in 3,748 cases (76%). Most common radiological patterns were parenchymal infiltrate in 5,017 (99%), and cavitation in 3,363 (66%). Unusual radiological patterns were also noted, i.e., lower lung field TB (LLFTB) in 317 cases (6.2%), pneumothorax in 78 cases (1.5%), and miliary pattern in 66 cases (1.3%). In conclusion, because of the more frequent occurrence in the younger age group, it is considered that the prevalence of disease is still high and that the transmission of tubercle bacilli is not decreasing in our region. The highest risk group consisted of male subjects and those living in urban centres. The high percentage of active ex-patients suggests that new control programmes for tuberculosis are required in Turkey.