We report the results of a randomized controlled trial that compared the efficacy of an internet-based self-help treatment for paediatric headache including chat communication (cognitive-behavioural treatment, CBT) with an internet-based psychoeducation intervention (EDU). In the CBT group, significant pre- to post-treatment decreases were found for headache frequency and pain catastrophizing, but not for headache intensity or duration. In the EDU group none of the variables (frequency, intensity, duration, pain catastrophizing) showed improvement. No significant between group differences were found for headache variables and pain catastrophizing at post-treatment. The patients reported high satisfaction with the internet-based training and a good patient-trainer-alliance. Results were maintained at 6-month follow-up. Due to the small sample size, no general conclusions can be drawn regarding the efficacy of the internet-based training regarding the outcome variables, but the training was well accepted by patients. Further research is necessary to evaluate the therapeutic potential of such interventions.