Opioid analgesics are critical to the effective relief of cancer pain. Effective treatment is predicated on sound assessments, individually tailored analgesic therapy, and the availability and accessibility of the required medications. In some countries, pain relief is hampered by the lack of availability or barriers to the accessibility of opioid analgesics. As the follow-up to a successful project to evaluate the availability and accessibility of opioids and regulatory barriers in Europe, the European Society for Medical Oncology (ESMO) and the European Association for Palliative Care (EAPC) undertook to expand their research to those parts of the world where data were lacking regarding these aspects of care, in particular Africa, Asia, the Middle East, Latin America and the Caribbean, and the states of India. This project has been undertaken in collaboration with the Union for International Cancer Control (UICC), the Pain and Policy Studies Group (PPSG) of the University of Wisconsin, and the World Health Organization (WHO), together with a consortium of 17 international oncology and palliative care societies. This article describes the study methodology.