Following the criteria of the IHS, we studied 117 children (63 female and 54 male, mean age 9.35 +/- 1.65 years), selecting those classified as migraine (77) or tension-type headaches (30), total 107. We analysed the frequency of clinical manifestations with each type of headache (type and localization of pain, severity of the headache--intensity, duration and degree of disability--and associated symptoms) and their contribution to the differential diagnosis of each entity (evaluated as the presence--sensitivity--or absence--specificity--of each clinical manifestation in each group). Our study shows that throbbing headache (49%) and a unilateral location (31%) as well as nausea and vomiting (33.6%), although constituting diagnostic criteria of migraine, according to the IHS, have acceptable sensibility (91-95%), but only slight specificity (34-40%) for infantile migraine. On the other hand, we found that a greater intensity of headache (22%), and the presence of abdominal pain (15%) as associated symptom, although not considered diagnostic criteria, are also parameters of high sensitivity (100-92%) respectively, and also of greater specificity (30-70%) than the anterior criteria. We conclude that the criteria of IHS for the diagnosis of headache in infancy may be valid although some considerations are necessary. The new IHS criteria for the headache diagnosis in adults [1] may be useful in pediatric age, but the experience on this use is spare, consequently the increment on the use of this classification and the future changes, could produce a best operativity in the diagnosis of headache in childrens.