The main problem in organ transplantation is the continuing shortage of organ donors. Despite all efforts no major significant increases in organ availability are observed during the year 1996 in the participating Eurotransplant counties, while the demand i.e. the waiting lists are still increasing. Shortage of organs will also have its effects and constraints on the distribution i.e. the allocation of scarce organs. To meet the demand of the renal transplantation programs a special kidney allocation system was designed based upon many simulation studies. Already a few months after implementation of the new system very promising results were observed i.e. the discrepancies between the different countries in terms of kidney procurement and transplantation frequencies disappeared. Furthermore, twice as much long waiting kidney patients have been transplanted as previously and the percentage of well matched HLA donor-recipient combinations remained surprisingly high, nearly 24%.