The incidence of pulmonary tuberculosis (TB) is decreasing in Western Europe. However, TB should not be considered to be a rare disease, particularly in immigrants and in immunocompromised persons (i.e. HIV infection). The clinical presentation is often atypical in immunocompromised persons. In general, the extent of the disease is underestimated by the clinical presentation. X-ray and a sequential investigation of three samples of sputum including microscopy, culture and susceptibility testing for the first-line drugs should be obtained. Tuberculin testing is useful in the diagnosis of latent TB and in screening persons with close contact to patients with active disease. New blood tests based on the detection of interferon-g released by antigen specific T-cells have some advantages compared to tuberculin testing.