Bruises in children are commonly seen and mainly caused by minor injury. However, they might be the first sign of a coagulopathy. Therefore, it is necessary to distinguish between normal bruises and relevant bleeding symptoms. Apart from the clinical examination, a detailed, standardized history of both the child and its family is mandatory. If a bleeding disorder is suspected, extended coagulation tests are necessary, because conventional screening tests (activated partial thromboplastin time (aPTT) and Quick) cannot exclude common disorders like von Willebrand disease. In the following contribution, the necessary diagnostic procedures with an emphasis on relatively common disorders are described.