Living organ donation has developed into an important therapeutic option in transplantation medicine. However, there are some medico-ethical problems that come along with the increasing reliance on this organ source. One of these concerns is based on the observation that many more women than men function as living organ donors. Whereas discrimination and differential access have been extensively discussed in the context of cadaveric transplantation and other areas of health care, the issue of gender imbalance in living organ donation has received less attention. This paper presents relevant data from the Eurotransplant and UNOS transplantation systems (1) and discusses possible explanations for the documented gender discrepancies. The conclusion calls for a review of existing practice guidelines in order to secure effective protection of particularly vulnerable potential donors and an equitable donor-recipient-ratio in living organ donation.