Background: The aim of the present study was to evaluate the sensitivity and specificity of the Strengths and Difficulties Questionnaire (SDQ) in detecting emotional and behavioural problems among children with chronic illness (CI). Methods: Parents and teachers of a population of primary school children in Norway (n = 9430) completed a questionnaire including the SDQ, and a question about chronic illness. A total of 74% (n = 7007) of the parents participated. A sub-sample (n = 1040) was given a psychiatric diagnostic evaluation according to the Development and Well-Being Assessment (DAWBA). Results: According to parent reports, 537 (8%) children had a CI. The SDQ revealed an increased risk of emotional and behavioural problems in children with CI as compared with non-CI peers, both among boys (OR = 2.10 CI 95% 1.56-2.83) and girls (OR = 2.11 CI 95% 1.49-2.99). Children with CI also showed an increased risk of psychiatric disorder as assessed by the DAWBA (OR = 1.70 CI 95% 1.04-2.85). Both the sensitivity and specificity of the SDQ in predicting a psychiatric diagnosis were high, even when only information from parents was included. Conclusion: Children with CI in the general population are at increased risk of behavioural and emotional problems and psychiatric disorders. Given its high sensitivity and specificity the SDQ might work well as a screening instrument for behaviour/emotional problems and psychiatric disorder in children with CI.