Prescription drug abuse has reached an epidemic level in the United States. The prevalence of prescription drug abuse escalated rapidly beginning in the late 1990s, requiring a significant increase in research to better understand the nature and treatment of this problem. Since this time, a research literature has begun to develop and has provided important information about how prescription drug abuse is similar to, and different from the abuse of other substances. This introduction to a special issue of the Journal of Substance Abuse Treatment on prescription drug abuse provides an overview of the current status of the research literature in this area. The papers in this special issue include a sampling of the latest research on the epidemiology, clinical correlates, treatment, and public policy considerations of prescription drug abuse. Although much has been learned about prescription drug abuse in recent years, this research remains in early stages, particularly with respect to understanding effective treatments for this population. Future research priorities include studies on the interaction of prescription drugs with other licit and illicit substances, the impact of prescription drug abuse across the lifespan, the optimal treatment for prescription drug abuse and co-occurring conditions, and effective public policy initiatives for reducing prescription drug abuse.