Modern DNA technology allows the analysis of minute biological trace samples. In sex crimes where witnesses or other facts might be missing, evidence such as DNA can prove crucial in solving a case. A matching DNA profile is very strong evidence, and the proper collection and handling of potential evidence has thus become even more critical for forensic medical examiners and gynaecologists. In Sweden, ready-to-use kits for the sampling of potential evidence after a sex crime have been in use for some years. A presentation at the Tempus Phare Project in Cracow, September, 2000, to familiarise Polish prosecutors with the sexual assault kits, attracted much attention. In this paper, the background and experiences with sexual assault kits in Sweden are presented.