The development of motivational interviewing (MI) has contributed to a significant change in the zeitgeist of substance abuse treatment. Dr. William Miller has been instrumental in the direction MI has taken. Dr. Miller helped develop MI, guide research and training initiatives, and as a result set a solid foundation for the future of MI. In this article, an interview with Dr. Miller is provided, in which he reflects on his career as he prepares for retirement and provides his perspective on the future of substance abuse treatment and training. Dr. Miller's recommendations for training therapists in MI are also highlighted.