Over the past few years, Canada and the United States have been experiencing an opioid crisis as a result of problematic opioid use fueled by the emergence of synthetic opioids such as fentanyl and carfentanil. Problematic opioid use is also spreading in other OECD countries, due to the upward trend of prescription opioid use and the complexities of the illegal drug supply. This report presents evidence on the magnitude of problematic opioid use across OECD countries, describes the main drivers, and identifies a set of policy actions to address them. The report highlights the opioid crisis as a complex public health issue that requires a comprehensive approach across all sectors, including health, social services, and law enforcement. Strong health information systems are also needed, particularly data and research. Preventing problematic opioid use requires a combination of policies that ensure more information is provided to patients and health care practitioners, while providing access to appropriate pain management treatment for patients. A public health approach to problematic opioid use must incorporate socio-economic considerations (e.g. employment and housing), which also need to be addressed to prevent problematic substance use in general.