PURPOSE: The purpose of this study was to evaluate the clinical characteristics and efficacy of prophylactic treatment of pediatric chronic daily headache (CDH). METHODS: A retrospective medical-record review of patients who underwent the prophylaxis after a diagnosis of CDH was performed. Response to treatment was assessed by the total number of headache days/month. More than 50% reduction of headache frequency was classified as responders. RESULTS: Eighty patients with the diagnosis of CDH were included in the study. CDH was more prevalent in girls than in boys. It was classified into chronic migraine (81.2%), chronic tension-type headache (15.0%), or new-onset persistent daily headache (3.7%). None of the patient fulfilled the diagnostic criteria of hemicrania continua. The mean age of the patients was 11.8+/-1.2 years. The mean number of monthly headache episodes before treatment was 25.5+/-4.4. After prophylactic treatment, headache episodes were reduced to 8.7+/-9.5 episodes per month. The responder rate of prophylactic treatment was 70.2% (55/80 patients) for either topiramate or flunarizine. CONCLUSION: In our study, the most common type of CDH was chronic migraine. All patients with CDH had frequent, long lasting migraine attacks. This study also suggests that prophylactic treatment is effective in the treatment of pediatric CDH.