The aim of this study was to evaluate the concordance between clinical diagnosis and the International Classification of Headache Disorders, 2nd edn (ICHD-II) in children and adolescents with primary headaches. This 6-month prospective multicentre study of 486 patients (mean 9.8 +/- 3.1 years; 52.6% girls) assessed the headache features through a structured questionnaire. In 398 patients with a single type of headache, headaches were bilateral (78.1%), frontal (62.4%), pulsatile (56.1%), with associated symptoms in 84.4%. The most frequently assigned diagnoses were migraine without aura (50.8%), probable migraine (14.1%), migraine with aura (11.1%) and frequent episodic tension-type headache (7.5%). For most of the diagnostic categories, the consistency of the investigator's diagnosis with the ICHD-II criteria was good (kappa > 0.6 and < or = 0.8) or excellent (kappa > 0.8). We conclude that migraine was predominant with regard to headache diagnoses repartition and that the ICHD-II seems usable in practice for evaluation of primary headache in French children and adolescents.