Both tuberculosis and bronchiectasis carry a significant burden worldwide in terms of morbidity and mortality, as well as financial, especially in the developing world. Epidemiological data for tuberculosis are now more readily available since the World Health Organisation declared it 'a global emergency' in 1993. The global prevalence of bronchiectasis, a recognized sequel of tuberculosis, is unknown, but is by no means insignificant. The pathophysiology of chronic airflow obstruction in both of these diseases is poorly understood, but it is associated with an accelerated rate of loss in pulmonary function. This article examines the global burden of tuberculosis and bronchiectasis, and focuses on the interrelation with chronic airflow obstruction.