OBJECTIVE: To examine the factor structure of the self-report Strengths and Difficulties Questionnaire (SDQ) for data from a sample of British children aged 6-10 years. METHOD: The self-report SDQ was administered to 900 children aged 6-10 years via interviews with trained counsellors. RESULTS: Confirmatory and exploratory factor analyses showed that a two-factor solution comprising ‘externalizing and peer problems’ and ‘internalizing problems’ fit the data well for both the 6- to 7- and 8- to 10-year-old samples. The factors were correlated in both samples. CONCLUSIONS: Children between 6 and 10 years of age provided meaningful SDQ data. The identified two-factor model maps broadly onto the constructs of externalizing and internalizing behaviour.