Chronic daily headache (CDH) affects 2-4% of adolescent females and 0.8-2% of adolescent males. Chronic daily headache is diagnosed when headaches occur more than 4h/day, 15 headache days per month or more, over a period of 3 consecutive months, without an underlying pathology. It is manifested by severe intermittent, migraine-like headaches as well as by chronic baseline headaches. Both Silberstein-Lipton criteria and the second edition of the International Classification of Headache Disorders (ICHD) can be used to classify chronic daily headache in children and adolescents. Chronic daily headache is classified into four diagnostic categories: transformed (Silberstein-Lipton criteria)/chronic (ICHD) migraine, chronic tension-type headache, new daily persistent headache, and hemicrania continua. Children and adolescents with chronic daily headache frequently have sleep disturbance, pain at other sites, dizziness, medication-overuse headache, and a psychiatric comorbidity (anxiety and mood disorders). Chronic daily headache frequently results in school absence. Successful approaches to treatment include reassurance, education, use of preventative medication, avoidance of analgesics, and helping the child return to a functional daily routine and a regular school schedule.