This article examines the relationships between child marriage, agency, and schooling in rural Honduras. Through an in-depth qualitative case study, we address the following questions: (1) In what ways, if any, do girls exercise agency in their decision to marry? (2) How might education enhance girls' agency, expanding their choice sets and delaying the age of marriage? We argue that a lack of understanding of the decision-making processes of young girls impedes the design and implementation of interventions to address child marriage. Our in-depth, qualitative case study allows us to document how the agency that girls exercise is simultaneously thin, opportunistic, accommodating, and oppositional. Returning to Ahearn's notion of agency as the socioculturally mediated capacity to act (2001a, 112), our findings suggest that for education to enhance adolescent girls' agency it must transform the sociocultural conditions that constrain their actions, targeting individual girls, families, and communities.