With funding from Shire Development, LLC, our researchers investigated nonmedical prescription drug use in five European countries—Denmark, Germany, Spain, Sweden, and the United Kingdom. Our findings suggest that rates of opioid abuse in the EU may be catching up to rates in the United States. Understanding the scope and prevalence of nonmedical prescription drug use in the EU is an important step toward building a worldwide system that can be used to monitor trends, track risk and protective factors, and develop interventions.