Male Asian elephant (Elephas maximus) sociality is complex and understudied. Increasingly, researchers recognize the role of mature bull elephants in shaping adolescent males’ appropriate social and reproductive behaviors that enable them to have normal intra-species relationships after the adolescents leave their natal herds. We describe a specific intervention event by a mature, dominant male in a novel social group with adolescent male elephants at Denver Zoo, Colorado, USA. The mature male intervened in an agonistic interaction between three adolescent males, which allowed an adolescent to escape from two other adolescents who were repeatedly chasing him. Such interventions by mature animals may serve to mark the boundaries of appropriate behavior for adolescent male elephants, and/or may serve to reduce group conflict and improve group stability. This behavioral observation provides an example of the type of social intervention by mature conspecifics from which adolescent male elephants might learn appropriate social behavior and suggests that mature males may play an active role in this relationship. Overall, this intervention behavior supports the inclusion of mature males in social groupings of male elephants in managed care.