Pulmonary tuberculosis is a common worldwide infection, causing high mortality and morbidity, especially in developing countries. Despite advances in diagnosis of tuberculosis, chest imaging, combined with the clinical history, remain the basis in the diagnosis, staging and follow-up of pulmonary tuberculosis. Typical radiological patterns of pulmonary tuberculosis help clinicians in management of the disease. Upper zone shadows, frequently bilateral and often associated with cavitation, are typical, as are miliary lesions. However, these findings are uncommon in childhood thoracic tuberculosis. The diagnosis of childhood intrathoracic tuberculosis depends on a constellation of symptoms, signs, and tuberculin skin test and chest radiograph results. Paratracheal, mediastinal, and hilar lymphadenopathy are frequent in childhood tuberculosis. In HIV-infected patients the radiological appearances are less specific, just as symptoms and signs may not be typical and sputum is often negative on direct smear. However chest computed tomography (CT) is frequently necessary to establish the need of additional tests. CT is more sensitive than chest X-ray in the detection and characterization of both slight localized or disseminated parenchymal disease and mediastinal lymphadenopathy. Eventually, nuclear medicine can be necessary since it provides tools for diagnosis and monitoring tuberculosis mainly in children, HIV immunecompromised individuals, tuberculosis sequel and suspected reactivation.