Decision making is a complex psychological process driven by emotions. Among the most unpleasant ones are the situations when the obtained outcome is not the one expected. This emotional experience is influenced by sense of agency, i.e. the feeling that we voluntarily control our actions and, through them, events in the world. Negative counterfactual emotions as disappointment have been marginally analyzed in children’s decision-making, and the study of children’s sense of agency could help to understand them.