People often evaluate a decision to commit an action more negatively than a decision to omit an action, given that both decisions have the same negative consequence. This phenomenon is called the omission bias. In the present experiments, subjects were not asked to justify their judgments in view of doubts about whether the processes underlying decision making are open to introspection. Instead, they were asked to rate an agent's immorality-or the anger evoked by the employer of the agent-as well as the agent's intention, causality, and responsibility for either a commission or an omission version of several scenarios. The results of the three experiments suggest that the basis of the omission bias is a difference in perceived causality, making the outcome of an omission appear less intended than the outcome of a commission. This reduction in perceived intention for outcomes of omissions might make the evaluation of someone's behavior less negative.