An increasingly large body of research in social psychology has underscored the power of brief situational interventions in promoting purposeful change. The present research contributes to the literature on positive psychology interventions (PPIs) by testing a novel volitional intervention that encourages people to engage in activities ‘outside their comfort zone.’ Participants were randomly assigned either to a condition that encouraged them to engage in an activity outside of their comfort zone over the following two weeks or to a control condition that encouraged them to keep a record of their daily activities. The intervention was found to boost the life satisfaction of people who were relatively less happy at baseline, with exploratory analyses tentatively suggesting benefits strongest among people who went outside their comfort zone by helping others. Discussion centers on the potential of behavioral ‘stretch’ interventions to promote positive change and well-being among people dissatisfied with their life. Overall, this study provides preliminary evidence for the potential benefits of intentionally and actively stepping out of one’s comfort zone. The findings have practical implications for therapeutic, organizational, and educational programs trying to improve life satisfaction and break people out of hedonic ruts and harmful routines. It is possible, moreover, that such stretch interventions may generate positive outcomes beyond greater life satisfaction. They may open people up to confronting challenging issues in their lives, forming new friendships, supporting others, and to being socially vulnerable—all possible consequences arising from the heightened sense of efficacy that may come from stepping outside their comfort zone