The diagnosis of childhood migraine cannot be confirmed in any objective way. The danger of missing brain tumours or cerebral vascular malformations in these patients was examined in two groups. 73 children who were diagnosed as childhood migraine were followed for 5.4 years. No brain tumour or vascular malformation was found, but two children diagnosed as "abdominal migraine" had a different important disease. The charts of 83 children with brain tumours and seven children with vascular malformations were examined. Only three children could be confused with migraine, and only one actually was.