We conducted a clinic-based study focusing on the clinical features of new-onset chronic daily headaches (CDH) in children and adolescents. The clinical records and headache diaries of 306 children and adolescents were reviewed, to identify 187 with CDH. Relevant information was transferred to a standardized form that included operational criteria for the diagnoses of the headaches. Since we were interested in describing the clinical features of these headaches, we followed the criteria A and B of the 2nd edn of the International Classification of Headache Disorders (ICHD-2) and refer to them as new daily persistent headaches (NDPH) regardless of the presence of migraine features (therefore, this is a modified version of the ICHD-2 criteria). From the 56 adolescents with NDPH, most (91.8%) did not overuse medications. Nearly half (48.1%) reported they could recall the month when their headaches started. NDPH was more common than chronic tension-type headache in both adolescents overusing and not overusing medication. Individuals with NDPH had headaches fulfilling criteria for migraine on an average of 18.5 days per month. On most days, they had migraine-associated symptoms (one of nausea, photophobia or phonophobia)). NDPH is common in children and adolescents with CDH. Most subjects do not overuse medication. Migraine features are common.