This study investigated the change in feelings of regret over time in relation to decision-making style, critical thinking, behavior, and coping methods with the regret. Seventy undergraduate students completed a questionnaire on critical thinking, decision-making styles, feelings of regret and the coping methods in five different situations: entrance examinations, declarations of love, skiing, career changes, and investments. Results showed the following. First, in situations which normally occur only once (i.e., entrance examinations), subjects who indicated inaction felt increased regret over time, but those who indicated action felt decreased regret. Conversely, in situations which occur regularly (i.e., declarations of love and skiing), both of those who indicated action and inaction felt decreased regret. Second, people who indicated action coped with their regret using the method of rationalization more often than those who indicated inaction. In situations which normally occur only once, analytic decision-makers tended to cope with their regret by improving their behavior more than intuitive decision-makers. Finally, critical thinkers tended to adopt an analytic style more often than an intuitive style.