||People tend to overestimate emotional responses to future events. This study examined whether such affective forecasting errors occur for feelings of regret, as measured by self-report and subsequent decision-making. Some participants played a pricing game and lost by a narrow or wide margin, while others were asked to imagine losing by either margin. Participants who experienced a narrow loss reported more regret than those who imagined a narrow loss. Further, those experiencing a narrow loss behaved more cautiously in a subsequent gambling task. Thus, this study provides self-report and behavioral evidence for a reversal of the affective forecasting phenomenon for the feeling of regret.