This study investigates the effect of outcome knowledge on auditors' judgments. Specifically, we varied the degree of surprise of the outcome to determine its effect on hindsight judgments in an auditing task. Results indicate that when the outcome is surprising, ex ante judgements are affected, However, when the outcome is not surprising, foresight and hindsight evaluations are not significantly different. We also tested a simple decision aid designed to reduce the hindsight effect. While the results were weak, we were able to move foresight judgments in the direction of the related hindsight judgment