AIM: To suggest diagnostic combinations of symptoms for migraine and tension type headache (TTH), and for differentiation of overlapping headache (classifi ed as either migraine or TTH) through evaluation of the diagnostic value of combinations of characteristics included in the International Headache Society diagnostic criteria for migraine and TTH in children and adolescents. PATIENTS AND METHODS: The study comprised an epidemiological school-based study (412 of 1029 pupils with chronic / recurrent headache) and a clinical study conducted in the Pediatric Neurology Ward and outpatient clinic at Plovdiv Medical University Hospital (203 patients with chronic / recurrent headache). An inclusion criterion was at least two episodes of headache during the last year. Exclusion criteria were: headache occurring only during acute infections; withdrawal of informed consent. Headache was classifi ed according to the International Classifi cation of Headache Disorders 2 nd edition (ICHD-II) The diagnostic value of all combinations of items in criteria C and D for migraine and TTH was measured by sensitivity, specifi city, and odds ratio. RESULTS: The combination "unilateral location, severe intensity, aggravation by physical activity" had 100% specifi city for migraine. The combination "bilateral location, pressingtightening quality, mild intensity, no aggravation by physical activity" had 100% specifi city for TTH. The combinations: "migrainous location, severe intensity, aggravation by physical activity", "severe intensity, nausea", "pulsating quality, nausea", "pulsating quality, migrainous location, aggravation by physical activity" seemed to pose the greatest risk for developing migraine. These combinations -"no nausea, no photophobia", "bilateral location, mild intensity and either no aggravation by physical activity or pressing-tightening quality, or no nausea or no photophobia" increased the most the TTH risk. Using these combinations as additional criteria for overlapping headache we classifi ed 50% of overlapping headache as TTH and 8.3% as migraine. CONCLUSIONS: Some combinations of symptoms clarify the diagnosis of migraine and TTH. More than 50% of overlapping headache could be differentiated as TTH or MWA by the proposed combinations.