Designing the best evaluation for a specific organ donation activity can reflect practical considerations as well as principles of scientific rigor. Every organ donation activity can be evaluated with some degree of rigor and every existing evaluation can be improved. The degree to which these studies are evaluated depends largely on the appropriate balance of study strength, available resources and other practical constraints. The guidelines set forth in this paper are not rigid standards. They are by no means exhaustive, but represent strengths and weaknesses of alternative approaches to meet the challenge of evaluating organ donation programs.