The authors present the possibilities of applying positron emission tomography (PET) in oncopulmonology. In addition to reviewing the literature, they share their own experience obtained during the diagnostic work-up and follow-up of twenty-three patients. The basic indications and the relevant properties of the most frequently used radiopharmaceuticals are discussed. Finally, the authors raise the question of cost-effectiveness of PET-investigations vs. conventional techniques, and suggest possible algorithms to include this non-invasive imaging method in the diagnostic work-up of patients with malignant or benign pulmonary diseases.