The harvesting of organs for transplantation is dependent on a stringent definition of brain death. Different societies have had to struggle with their cultural heritage, adapting it to conform to the advances in medical science and the need of the sick. In this article, the development of the concept of brain death as it applies to organ transplantation in Judaism is outlined. The ability of traditional Jewish values to address themselves to the challenges of modern medicine can serve as a basis for cultural cross-fertilization and comparison in modern societies.