This article examines the relationship between the principle of double effect and justification for separation surgeries for conjoined twins. First, the principle of double effect is examined in light of its historical context. It is argued that it can only operate under an absolutist view of good and evil that is compatible with the Bible. Given this foundation for application, scenarios for separating conjoined twins are considered against the criteria for the principle of double effect. It is concluded that the principle of double effect cannot be applied to cases wherein one of the twins must be killed. However, it is noted that this does not leave decision makers without options.