Behaviour and other developmental problems are common in preschoolers and may have a positive outcome if they are treated early. However, they often go undetected. Thus, the need for valid and reliable screening instruments for this age range is urgent. The Strengths and Difficulties Questionnaire (SDQ; Goodman, 1997) is a brief behavioural screening questionnaire about 3-16 year olds. It includes 25 items on the following five psychological attributes: emotional symptoms, conduct problems, hyperactivity / inattention, peer relationship problems and prosocial behaviour, which, added together, generate a total difficulties score. Several versions exist, for completion by parents, teachers and adolescents themselves. The SDQ is a widley used instrument and normative data have been obtained from several countries. The aim of the present study was twofold: a) to assess the SDQ as a potential means for improving the detection of child behaviour problems in the community and b) to provide normative data on several behaviour problems in Greek preschoolers. The nursery teachers of 974 children and the mothers of 787 children (N=1761) aged 3-6, enrolled in kindergartens and nursery schools in Athens, filled in the questionnaires for each child. Age and gender distributions were as follows: m=56.97 months, s.d. = 9.79; 52.2% males, 47.8% females. In general, our investigation showed that a Greek translation of the teacher version of the SDQ worked well. According to descriptive analysis, 11.7% of the sample presented some kind of behaviour problems. The most common were conduct problems (16.9%) and hyperactivity / inattention (12.1%) with boys outnumbering by far girls and with nursery teachers reporting more frequently problems of the above types than mothers. To conclude, the study gives further evidence of the usefulness of the SDQ as a promising screening instrument for epidemiological research and clinical purposes and indicates the developmental disabilites that need specific attention in preschoolers.