This expert opinion report examines the current realities of the cancer pain management landscape and the various factors that hinder optimal pain control in six countries in Southeast Asia, describes ongoing efforts to advance patient care, and discusses approaches for improving cancer pain management. Information was gathered from leading experts in the field of cancer pain management in each country through an initial meeting and subsequent e-mail discussions. Overall, there are vast disparities in cancer pain management practices and access to opioids in the Southeast Asian countries. The experts considered cancer pain as being generally undermanaged. Access to opioids is inadequate in most countries, and opioid use for analgesia remains inadequate in the region. Several system-, physician-, and patient-related barriers to adequate pain relief were identified, including widespread over-regulation of opioid use, shortage of trained health care workers, inadequacies in pain assessment and knowledge about managing pain, and widespread resistance among patients and physicians toward opioid treatment. According to the experts, many of the ongoing initiatives in the Southeast Asian countries are related to educating patients and physicians on cancer pain management and opioid use. Efforts to improve opioid availability and reduce regulatory barriers in the region are limited, and much work is still needed to improve the status of cancer pain management in the region. Enacting necessary change will require recognition of the unique needs and resources of each country and collaboration across interdisciplinary professional teams to improve cancer pain care in this region.