The Jehovah's Witness Christian movement was founded in North Eastern USA more than 120 years ago. It developed a worldwide following and now has more than 5.9 million members in 230 countries. A fundamental belief of the faith is the rejection of blood transfusions and certain other blood products. This is based on biblical teaching (Genesis 9: 3, 4; Leviticus 17: 11, 12; Acts 15: 28, 29). In the past, some other medical treatments were also banned. For example, vaccinations were banned from 1929 to 1952 and organ transplants were banned from 1967 to 1980. However, it is the policy concerning refusal of blood that is most associated with the movement. This policy dates from 1945 and was rigorously enforced from 1961. Administration of blood products to an individual led to that person being excommunicated from the church, followed by ‘enforced shunning’ and social isolation because other members were instructed to ostracize the expelled individual. In June 2000, a change in this policy was announced by the headquarters of the church, the Watchtower and Bible Tract Society. Although acceptance of blood products through personal choice still means disassociation from the church, if the individual repents, spiritual support is offered and subsequent redemption is possible. Furthermore, it is the individual who now revokes his or her own membership through self-disclosure, rather than the congregation initiating ‘disfellowshipping’ through a judicial committee. Therefore, if the act of receiving blood is kept confidential, disassociation is highly unlikely. The importance of medical confidentiality cannot be stressed too strongly.