Little is known about behavioural and emotional adjustment in children in Sri Lanka, and this study is the first attempt to assess mental health problems in this population. Using the Strengths and Difficulties Questionnaire (Goodman R (1994) A modified version of the Rutter parent questionnaire including items on children's strengths: a research note. J Child Psychol Psychiatry 35:1483-1494) with parent, teacher and child informants, in a large sample of 10- to 13-year-old school children from Colombo, we found rates and types of problems consistent with other international studies of child mental health. Problem rates were higher in boys and were associated with lower SES and poorer academic performance. Relationships between behavioural adjustment and Tamil ethnicity and Hindu religion emerged in this sample and could possibly be associated with the experience of longstanding ethnic conflict in Sri Lanka. The study confirms the need for development of child and adolescent health services in Sri Lanka.