The Strengths and Difficulties Questionnaire (SDQ) is an internationally widely used, brief screening instrument for mental health problems in children and teenagers. The SDQ probes behaviours and psychological attributes reflecting the child's difficulties as well as strengths, and targets hyperactivity/inattention, emotional symptoms, conduct problems, peer problems and prosocial behaviour. Also, the instrument taps the impact aspect, i.e. whether the child is judged to suffer from emotional or behavioural problems severe enough to cause distress or social impairment. Studies of the original English SDQ, as well as of translations into several other languages, attest to a compelling usefulness and validity of the instrument. In this investigation, the adequacy of the Swedish adaptation of the SDQ (SDQ-Swe) was tested in comparisons between parent reports on 5-15-year-old children drawn from a community sample (n=263) and from a child psychiatric sample (n=230). Results showed that the instrument differentiated well between the community and the psychiatric samples, the latter displaying more symptoms, fewer strengths and more social impairment. Moreover, ROC analyses showed satisfactory sensitivity and specificity of the principal scales of the SDQ-Swe at proposed cut-offs. Hence, results showed adequate validity of the SDQ-Swe, suggesting that this new instrument, an instrument in tune with the ideas of contemporary child psychiatry and psychology, is a useful tool for mental health screening in children and adolescents.