OBJECTIVES: To investigate the scale and socioeconomic cost of untreated/uncontrolled chronic pain. METHODS: We performed a systematic literature search in PubMed to identify studies reporting the economic cost of pain globally and in Asia Pacific. RESULTS: Prevalence estimates for chronic pain among adults range from 2-40% in the US and 12-30% in Europe, with similar rates reported in Hong Kong (10.8%) and Singapore (8.7%). Chronic pain is costly not only because it requires medical treatment and complicates treatment for other conditions, but because it undermines the ability to lead a productive working and social life, placing a substantial burden on individuals, employers, healthcare systems and societies in general. Despite the personal and socioeconomic impact of chronic pain, a large proportion of patients remain untreated. A third of chronic pain patients in a European survey were currently not treated, while around half of patients with cancer pain are undertreated. Poor availability of medications due to cost, licensing, prescribing regulations, lack of training for healthcare workers and cultural factors are causes of undertreatment, especially in the developing world.  The majority of countries in Asia have limited or very limited availability of medicines for moderate to severe pain and no national palliative care policies. The costs associated with chronic pain in terms of direct healthcare and indirect costs are huge, estimated at $560-635 billion annually in the US and as much as €300 billion in Europe, and representing 3-10% of gross domestic product. Chronic pain therefore represents an economic burden at least as great as priority health conditions such as heart disease, cancer and diabetes. CONCLUSIONS: A strategic approach is required to counter the unacceptable burden of uncontrolled chronic pain at the national and international level, alongside further research and education into effective treatment, management and prevention of pain.