The medical literature provides little information on manifestations of hereditary hemorrhagic telangiectasia (HHT) in children. The presented investigation was initiated to analyze early presenting symptoms in HHT, which should help to make the diagnosis at a young age and thus prevent potential complications from occult visceral arteriovenous malformations (AVM), which have commonly been described in HHT. A series of 15 children and adolescents with a suspicious diagnosis of HHT were examined clinically for typical signs and symptoms of the disorder. If the diagnosis of HHT seemed to be likely, recommendations for non-invasive screening procedures were given. Screening was directed at the detection of occult visceral AVMs. Main outcome measures were the definition of principal signs of HHT in children and adolescents. Family history was positive for HHT in 13 persons. The principal sign of recurrent epistaxis was present in 10/15 individuals and the earliest age of onset with regard to epistaxis was 4 years. Cutaneous vascular lesions were present in 5/15 patients. Screening for AVMs was performed in six individuals and revealed vascular lesions of the brain in two patients and vascular lesions of the lung in two patients. Gastrointestinal hemorrhages were present in one infant. Based on these findings, diagnosis of HHT seemed likely in ten individuals and unlikely in five individuals. Signs and symptoms of HHT in children and adolescents may be discrete, but are detectable at an earlier age than previously thought. Clinical examinations in children from HHT families may help identify candidates who will benefit from molecular genetic testing or screening imaging studies.