Nearly 2% of youths suffer from chronic migraine or chronic tension-type headache (CTTH). A contributing factor in approximately 20%-50% of these youths is medication overuse, which involves taking analgesics three or more times per week for three months. The objective of this study was to test motivational interviewing (MI) as an approach to promote adherence to recommendations regarding not only analgesic overuse but also other aspects of treatment plans. A randomized controlled trial was conducted comparing the experimental condition (standard of care clinic-based treatment with supplemental MI phone calls; N = 24) to a control condition (standard of care clinic-based treatment without these supplemental MI phone calls; N = 23). Four months after enrollment, a research assistant who was blinded to study condition telephoned adolescents inquiring about headache frequency, headache severity, and disability. Headache frequency was lower in the experimental condition versus control condition for those with relatively lower initial levels of headache frequency. In contrast, we did not find greater improvement in headache severity and disability for the experimental condition relative to the control condition. Our findings provided some preliminary, albeit limited, support for MI as an approach to improve outcomes for adolescent medication-overuse headache (MOH).