This review of the literature covers classification, epidemiology and clinical aspects of idiopathic headache in childhood and adolescence. In addition, pathogenetic models taking into account the complex involvement of organic, psychological and psychosocial factors are critically reviewed. A general pathogenetic model of migraine may be characterized by a given predisposition, various co-factors which enhance the tendency, and finally, trigger mechanisms which induce an attack. No generally accepted model exists for tension-type headache. In assessing the importance of various factors thought to be related to idiopathic headache, it is necessary to differentiate between causal relation, unspecific association, and coincidence. The aim of this review is to present potential factors influencing headache in childhood and adolescence and to discuss these factors critically with regard to their etiopathogenetic importance. Organic factors seem to be most important in migraine, whereas psychological and (psycho)social factors may influence any type of headache. Briefly, migraine in childhood and adolescence seems to be definitively associated with vegetative dysfunction, abdominal symptoms and hormonal factors and possibly with allergic reactions, whereas a relation to epilepsy can be excluded. There is absolutely no evidence for a typical personality of migraine patients. Various psychic reactions, however, are important in all types of headache. Depression and anxiety in young headache patients seem to be related generally to pain, but not specifically to headache. However, school problems, learning disabilities and stress coping behaviour seem to be related directly to recurrent headache. Additionally, there is evidence that the prevalence of headache is associated with low economic status.