The study examined the extent to which a service trip to Nicaragua affected college students' narrative understanding of themselves and their commitment to volunteer service. College students who went on a spring break service trip to work with poor citizens of Nicaragua wrote narrative accounts of three important experiences on the trip shortly after they returned. Measures of volunteerism were collected before the trip and at two points afterward: 1 week and 3 months later. Themes of self-transformation in service trip narratives predicted trip-related volunteerism one week and 3 months later, even after controlling for prior volunteerism. Themes of sympathy in the narratives predicted trip-related volunteerism one week but not 3 months, and themes of helplessness negatively related to prior volunteerism. The results underscore the importance of examining the role of life narratives in the development of volunteer behavior and service mindedness among emerging adults. (Contains 2 notes, 3 tables, and 2 figures.)