Human organs for transplant are presently distributed by means of manual handling and telephone-fax transmission of data related to the donor. This procedure is conducted organ by organ and the information is transmitted sequentially to the transplant teams. The main drawback of this procedure is the long length of time taken to allocate the organs on many occasions. The main objective of this work, CARREL, is to increase the efficiency, safety, rapidity and quality of organ distribution, thereby helping the allocation process. CARREL is a data-base system, accessible through Internet, to which any medical center authorised to perform organ transplants could subscribe. CARREL allows to share medical information between centers. This information includes administrative, anthropometric, immunological, analytical, radiological and clinical data of donors and recipients, as well as data concerning the follow-up reports of already-transplanted patients. The CARREL prototype has now been fully developed. The data-base can manage complete information concerning both donation and transplantation processes. Matching algorithms and allocation mechanisms have been implemented. CARREL can provide an alternative organ distribution procedure. This software must now be tested and validated by the government health authorities dealing with transplants, in order to be used by the full transplant community. CARREL is an online system which can reduce organ distribution time; it facilitates communication between transplant co-ordinators and transplant teams at different centres, thereby improving donor and organ evaluation, performing donor-recipient matching and hastening candidate selection.