The organization known as The Samaritans was established in 1953 in London by the Rev. Chad Varah as a suicide prevention service, but there is still an absence of data regarding the impact of this service on parasuicide (‘attempted suicide’). If it is hypothesized that the Samaritan organization does prevent parasuicide, it follows that an increase in Samaritan referrals would be associated with a decrease in parasuicide, other factors being equal. The recent B.B.C.1 programme based on the Samaritans afforded a natural experiment for testing this hypothesis.