Since the introduction of the high-resolution technique more than ten years ago, HRCT has become an established modality for diagnosing diseases of the respiratory system. This is especially true for the diagnosis of lung diseases in adults. Experience in HRCT of the lungs is limited in pediatric patients. This review gives an overview of frequent and less frequent HRCT findings in pulmonary diseases in childhood. A purely reticular pattern is rarely observed in infants. Pulmonary diseases associated with overinflation are relatively frequent. Paired inspiratory-expiratory scans combine morphological analysis with functional information and have improved the diagnosis of air trapping, e. g. in post-infectious bronchiolitis obliterans or bronchopulmonary dysplasia. Especially in children the high radiation exposure is a problem. Even when applying a low-dose protocol the radiation dose of HRCT will still exceed the dose of a chest X-ray by 100 times. The indication for pediatric pulmonary HRCT is limited to selected cases and it should be decided in agreement with the pediatric radiologists and the pediatric pulmonologists.