Some individuals with autism spectrum disorder (ASD) engage in verbal and physical aggression that is inimical to their educational and social development. Given that no specific treatment is applicable to all individuals with ASD, there is a need to develop and assess interventions that enable self-management of these behaviors. In a multiple-baseline design across participants, three adolescents with ASD were taught Surfing the Urge, an informal mindfulness practice, to self-manage their verbal and physical aggression. They were taught to use their breath as a surfboard to ride out the waves of aggression without engaging with or giving in to the urges to be verbally and/or physically aggressive. When compared to baseline, the results showed that following training in Surfing the Urge practice, the adolescents were able to produce clinically and statistically significant changes in both verbal and physical aggression. In addition, all three adolescents were able to discontinue the use of prescribed psychotropic medication when their physical aggression was reduced to very low levels. These results provide initial proof-of-concept data for the possible utility of Surfing the Urge practice for the self-management of verbal and physical aggression by adolescents with ASD.