How are judgments in moral dilemmas affected by uncertainty, as opposed to certainty? We tested the predictions of a consequentialist and deontological account using a hindsight paradigm. The key result is a hindsight effect in moral judgment. Participants in foresight, for whom the occurrence of negative side effects was uncertain, judged actions to be morally more permissible than participants in hindsight, who knew that negative side effects occurred. Conversely, when hindsight participants knew that no negative side effects occurred, they judged actions to be more permissible than participants in foresight. The second finding was a classical hindsight effect in probability estimates and a systematic relation between moral judgments and probability estimates. Importantly, while the hindsight effect in probability estimates was always present, a corresponding hindsight effect in moral judgments was only observed among “consequentialist” participants who indicated a cost-benefit trade-off as most important for their moral evaluation.