To estimate the prevalence of tension-type headache, migraine and other headaches, 1850 schoolchildren, age 7–15 years, from the city of Uppsala, were invited to complete a questionnaire. The response rate was 74.1%. To validate the information from the questionnaires, 131 children and their parents were interviewed. Using the criteria of the International Headache Society, the 1-year prevalence of tension-type headache and migraine was 9.8 and 11.0%, respectively. However, these prevalence rates increased considerably, to 23.0 and 17.0%, respectively, when excluding the criteria defining the number of earlier episodes and duration of headache. The prevalence of headache increased with age, similarly in girls and boys up to 11 years, and thereafter only in girls. The preponderance in teenage girls was even more pronounced for tension-type headache than for migraine. Our results indicate an increase over time in headache prevalence when compared with findings in a study conducted in the same city in 1955.