The assessment of suspected sexual child abuse demands teamwork where the paediatrician plays a central role. From a juridical point of view, the task of the paediatrician is to evaluate the anatomic, microbiologic and forensic medical findings. In 1995, in order to improve the quality of this work, Norwegian paediatricians established a peer review group which meets on a regular basis. Based on available literature and the experience of the individual members, a classification system for anogenital findings has been developed. The findings are divided into five classes. Class one comprises findings frequently seen in children who have not been abused. Class two comprises findings not considered to be normal, but for which there could be many different causes. Classes three, four and five represent findings which are increasingly predictive with respect to injury penetration or attempted penetration. Since our knowledge of anogenital anatomy in children who have not been abused is limited, our classification system should be updated regularly.