Pulmonary capillary haemangiomatosis (PCH) in childhood is a rarity, characterised by the uncontrolled proliferation of pulmonary microvessels which may invade pulmonary, bronchial and vascular structures, resulting in diffuse alveolar haemorrhage, manifesting clinically in haemoptysis, dyspnoea and symptoms of pulmonary hypertension (PH). A 14-year-old boy with some particular features (pericardial effusion and thrombocytopenia) is presented and 14 paediatric/adolescent cases from the literature are surveyed. The diagnostic problems and difficulties are discussed, including the importance of imaging (high-resolution CT) and histopathological studies, with the aim of providing a clear-cut distinction of PCH from other conditions such as primary PH (PPH). The literature data can be regarded as ambiguous: both similarities and relatively sharp distinctions between PCH and PPH are to be found. New developments in the field of genetics are also discussed. The early coexistence of PCH and other (vascular) disorders and associations, involving focal or diffuse, disseminated forms is summarised briefly. Conclusion. The diagnosis of this progressive disorder may lead to effective therapy. Treatment possibilities include the rapidly evolving field of anti-angiogenic therapy, but at present lung transplantation is universally accepted as the final definitive treatment for pulmonary capillary haemangiomatosis.