The study assessed reasons for delay between patient's first symptoms of tuberculosis and initiation of therapy. Fifty newly diagnosed cases of pulmonary tuberculosis admitted to the NRITLD in Teheran were studied. Mean patient delay before consulting a physician was 12.5 +/- 10 days, significantly higher among men than women. Mean delay until the physicians' diagnosis was 93 +/- 80 days, significantly higher for women than for men. Almost no treatment delay was observed (mean 4 +/- 4 days after diagnosis had been confirmed). The major delay was the time taken by physicians to diagnose tuberculosis in symptomatic patients. An active and effective national tuberculosis programme is needed in the Islamic Republic of Iran, with integration of the programme in medical school curricula and in continuing professional training.