In trolley dilemmas a train is about to kill several victims who could be saved if instead a different victim is harmed. A number of theories have been proposed which assume that permissibility judgments in these harm-based moral dilemmas are mediated by an analysis of the underlying causal structure. For example, it has been postulated that it is permissible to harm people as a side effect but not as a means. We have developed a different causal theory which claims that moral judgments are influenced by two contrasts, the global contrast between the number of victims in the presence and absence of the act, and an additional local contrast that compares the fates of the morally relevant target (i.e., threats, victims) of the proposed intervention in the presence versus absence of the act. This double causal contrast theory explains intuitions in various types of trolley dilemmas better than its competitors.