The clinical manifestations (both symptoms and signs) of infections of respiratory tract disease are limited and not specific to the cause. However, there is no universal approach, and good clinical judgment is often essential. Most people have approximately three colds per year, of which 70% result from viral origin. It should be stressed that a confident diagnosis of pneumonia is difficult outside the hospital. Very often the most important clinical questions are whether an antibiotic should be prescribed and should the patient be admitted to the hospital. A wide range of microbial pathogens can cause pulmonary infection. When bacteria are present, Haemophillus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis are most frequently found. For some patients atypical pathogens like Mycoplasma pneumoniae, Chlamydophilla pneumoniae and Legionella pneumophilla are also important. The role for microbial investigations has yet to be determined, but in most cases this may be needed only when the patient fails to respond to initial therapy. An approach to the diagnosis and treatment of pulmonary infections in Poland is presented in this study.