The discovery of plasma resistance towards activated protein C, APC resistance, and its main genetic background, the presence of a single-point mutation in the gene coding for coagulationfactor V, factor V Leiden, has, together with renewed documentation of a link between oral contraceptive use and thrombosis, increased the understanding of the pathophysiology, but also the demands to the prescribers, of the pill. Only with knowledge about hemostasis, thrombophilia, DNA technology, its use and limitations, epidemiology, and absolute risk,can general prac tition ers perform good clinical practice. This short survey tries to cover some of these aspects and to suggest directions for future research.