The breadth of dual-diagnosis issues found internationally and how they are manifest in three different national settings was the focus of a symposium at the American Society of Addiction Medicine (ASAM) 43rd Medical-Scientific Conference, which was held April 19–22, 2012, in Atlanta. Carlos Roncero, M.D., Ph.D., associate professor of psychiatry at the Autonomous University of Barcelona and chief of the drug addiction unit at Vall d’Hebron University Hospital, described the issues and treatment approaches in Spain. Giuseppe Carra, M.D., M.Sc., Ph.D., Monza Mental Health University Trust, Italy, described the dual-diagnosis treatment, service models, and research that have been developed in Italy over the past two decades. Haim Mell, M.D., head of treatment and rehabilitation at the Israeli National Anti-Drug Authority, discussed dual diagnosis in Israel. Other speakers included NIDA International Program Director Steven W. Gust, Ph.D.; Marc Galanter, M.D., New York University; and Jag Khalsa, Ph.D., NIDA Division of Pharmacotherapies and Medical Consequences of Drug Abuse. Dr. Galanter, Dr. Khalsa, and Petros Levounis, M.D., M.A., The Addiction Institute of New York, organized the symposium.