Decision outcomes sometimes result in negative emotions. This can occur when a decision appears to be wrong in retrospect, and/or when the obtained decision outcome does not live up to expectations. Regret and disappointment are the two emotions that are of central interest in the present article. Although these emotions have a lot in common, they also differ in ways that are relevant to decision making. In this article we review theories and empirical findings concerning regret and disappointment. We first discuss how regret and disappointment differ with respect to their antecedent conditions, appraisals, and phenomenology. We also discuss possible behavioural consequences of experiencing these emotions. Next, we consider how the anticipation of regret and disappointment may influence decision making. We use regret and disappointment theory, developed by the economists Bell (1982, 1985), and Loomes and Sugden (1982, 1986, 1987), as a framework for our discussion. Finally, we argue that combining the theoretical approaches and research paradigms of behavioural decision theory with emotion theories will significantly increase our knowledge of antecedents and consequences of emotions.