Pediatric pulmonary pathology is a challenging topic within pathology. There are several reasons; for example, these lung diseases are rare. Lung diseases in childhood do occur in two peaks: the first during the first two years of life, the second usually at the “Kindergarten” age. The first group comprises many developmental lung diseases, almost all of them based on genetic aberrations, whereas the second group includes diseases based on immune system dysfunction, infections, and rarely gene mutations. For infectious pulmonary diseases in childhood, a tissue analysis most often is not required. For the analysis of pediatric pulmonary diseases, the knowledge of lung development is essential, and the analysis of genetic abnormalities is becoming important.