After achieving sustained graft functioning in animal studies, the next step in the progression of xenotransplantation towards clinical application is the initiation of the first clinical trials. This raises the question according to which criteria patients shall be selected for these trials. While the discussion regarding medical criteria has already commenced, ethical considerations must also be taken into account. This is essential, first, to establish a procedure that is ethically reasonable and justified. Second, it is a prerequisite for a publicly (...) acceptable and comprehensible implementation. This paper outlines a multicriteria approach for the selection of patients in first-in-human clinical trials of cardiac xenotransplantation with four ethical criteria: medical need, capacity to benefit, patient choice and compliance (as an exclusion criterion). Consequently, these criteria identify a primary target group of patients who exhibit a high medical need for cardiac xenotransplantation, face a high risk of morbidity and mortality without an organ replcaement therapy, have a substantial chance of benefiting from xenotransplantation, thereby also enhancing the scientific value of the trial, and qualify for an allotransplant to have a real choice between participating in a first-in-human xenotransplantation trial and waiting for a human organ. A secondary group would include patients for whom only the first two criteria are met, that is, who have a high medical need and a good capacity to benefit from xenotransplantation but who have a restricted choice because they do not qualify for an allotransplant. (shrink)