Issues of what constitutes normal and healthy childhood sexual behaviour have acquired new implications in the light of child sexual abuse. Increased knowledge in this area is therefore of vital importance and studies in different countries are needed. In the present study parents of 231 children aged 3-6 y were asked to answer questionnaires about their child's behaviour at home. The questionnaire consisted of four sections: demographic data, a general behaviour checklist, a sexual behaviour inventory, and attitudinal questions to the parents. The results showed that children in Sweden exhibit a wide range of sexual behaviour, most of them developmentally related. Some behaviour appeared to be very rare in a normative sample of preschool children and included behaviours usually referred to as sexualized and problematic. Reports on sexual behaviour in the children were also related to general behaviour reports, the parent's socioeconomic level, parental attitudes towards child sexuality and the openness of family habits. Conclusion: There is a need for further national studies in different settings, to help create a better understanding of what constitutes both normative and deviant sexual behaviour in children.