Bacterial (including intracellular pathogens) and mainly viral pneumonia can lead to middle and long term pulmonary sequelae in children with or without underlying disease, namely chronic atelectasis (right middle lobe syndrome), bronchiectasis, obliterative bronchiolitis, unilateral hyperlucent lung syndrome, fibrosis, and peumatoceles. Functional alterations may also be observed, such as bronchial hyperreactivity, chronic cough and asthma. Additionally a relationship between pneumonia in early childhood and the further occurrence of chronic obstructive pulmonary disease in adult life is now admitted. The occurrence of sequelae being usually unpredictable, and a careful assessment of the clinical and radiological outcome is important. The unusual persistence of either respiratory symptoms or radiological alterations justifies investigations such as tomodensitometry and the evaluation of lung function, to look for complications or underlying diseases and, whenever it is possible, to set up an adapted treatment.