Objective To assess the prevalence, severity and impact of dental pain.DesignCross-sectional survey.SettingSchools in the London Borough of Harrow, England, in the summer term of 1995.Subjects and methodsThe base population were all 2,300 8-year-old school children in Harrow. A cluster sampling of schools based on quotas from all postcode areas in Harrow was used. Data were collected through interviews with the children.Main outcome measuresPrevalence of previous toothache; prevalence of toothache in the previous 4 weeks; prevalence of toothache in the previous 4 weeks which resulted in a visit to the dentist, in stopping playing, eating, sleeping, going to school and taking painkillers.ResultsOf the 664 sample of children in the participating schools, 589 were interviewed (88.7%). The frequency of previous toothache was 47.5% (95% CI, 44–52) and dental pain caused crying in 17.7% (95% CI, 15–21) of children. 7.6% (95% CI, 5–11) of children had pain in the previous 4 weeks (45 children). Among these 45 children, this recent pain resulted in a visit to the dentist in 41.9% (19 children, ie 3.2% of all children), in stopping playing in 26.7% (12 children, ie 2.0% of all children), eating in 73.3% (33 children, ie 5.6% of all children), sleeping in 31.1% (14 children, ie 2.4% of all children) and in going to school in 11.1% (5 children, ie 0.8% of all children).ConclusionToothache in children is a sizeable problem in Harrow and had substantial consequences for children and their guardians. Freedom from disabling dental pain/discomfort is an outcome indicator of oral health and could be used as an explicit goal by dental systems. It is important to note however, that the present study did not assess the extent to which the dental pain was associated with avoidable dental problems as opposed to normal physiological processes. It is important that future work try and separate the prevalence of dental pain caused by physiological from avoidable pathological factors. In addition, future work is needed to assess how effectively and efficiently dental services are responding to people suffering with dental pain.