Chronic daily headache (CDH), an almost continual headache in the absence of organic pathology, is an exceptionally challenging type of headache to treat in children and adolescents. CDH has different expressions in children and adults; the different expressions may reflect several different etiologies or a developmental continuum. Although a positive family history predisposes children to develop headache, many environmental, biological, and psychological processes may share a role in the etiology. To date, no studies have examined the pathophysiology of CDH in children so that our understanding is presumed, rather than documented, and based primarily on extrapolation from adult studies. For some cases with migraine features, presumed mechanisms include a neurogenic inflammatory cascade, vascular reactivity, and serotonin, whereas for other cases, mechanisms may include pericranial muscle tenderness or musculoskeletal abnormalities, as noted recently for adults. A skilled and careful history is the first step to ensuring an accurate diagnosis for children with CDH. Pain assessment is an integral component of diagnosis and treatment. We need an objective measure of headache activity and an understanding of the factors that cause or exacerbate headaches for an individual child. Although many drug and nondrug therapies are available for treating children's headache, we lack data about which therapies are best for children with CDH or its subtypes. The current principles guiding our management of CDH in children and adolescents are extrapolated from the existing literature on childhood headache, CDH in adults, and our clinical experience. A child-centered focus is particularly important in the treatment of CDH because it is not caused by an underlying disease or disorder.