Abstract Community Acquired Pneumonia (CAP) is a common childhood disease, involving several paediatric subspecialties in its diagnosis and treatment. This has prompted the Spanish Society of Paediatric Pulmonology (SENP) and the Spanish Society of Paediatric Infectious Diseases (SEIP) to prepare a consensus document on the diagnosis of CAP, assessing the practical aspects by means of evidence-based medicine. It discusses the aetiology and epidemiology, with the current changes and the validity of certain laboratory tests, such as acute phase reactants, microbiological and imaging techniques, guiding the paediatricians in the real value of these tests.