Limited research exists on self-monitoring interventions with incarcerated youth. In this pilot study, we implemented a randomized multiple-baseline design to investigate whether there is a functional relation between self-monitoring and an increase in the on-task behavior of three male students in a secure juvenile justice facility. The self-monitoring intervention consisted of a worksheet to track behavior, a watch to remind students to record their behavior every 5 minutes, and training in how to use the watch and worksheet. Results indicated the self-monitoring intervention was associated with an increase in on-task behavior across participants; there was an immediate and clear separation of levels between the baseline and intervention phases for all three participants. We discuss implications of these findings, as well as future directions for similar research in juvenile justice settings.