This research examines the appropriateness of confidence (i.e., subjective probability judgments) in knowledge associated with decisions and actions of social importance. One hundred and thirty seven participants completed a 50 item questionnaire assessing their knowledge of the two leading candidates in the 1988 presidential election in the U.S.A. Ninety one of the respondents completed the questionnaire one week prior to the election, whereas the other 46 completed the questionnaire on election day shortly after voting. After each item in the questionnaire, all respondents indicated whether or not the item content represented a reason why they voted (or intended to vote) for or against the candidate to whom the item referred. Within-person results indicated that, in comparison to items that were not cited as reasons for voting intentions or voting behavior, items endorsed as reasons were characterized by better accuracy and resolution, but worse overconfidence. Between groups, decision makers were significantly more accurate and better calibrated than those who had not made a decision between the candidates. Implications of inappropriate confidence on decision making effectiveness are discussed.