Betel quid and areca nut are known risk factors for many oral and oesophageal cancers, and their use is highly prevalent in the Asia-Pacific region. Additionally, betel quid and areca nut are associated with health effects on the cardiovascular, nervous, gastrointestinal, metabolic, respiratory, and reproductive systems. Unlike tobacco, for which the WHO Framework Convention on Tobacco Control provides evidence-based policies for reducing tobacco use, no global policy exists for the control of betel quid and areca nut use. Multidisciplinary research is needed to address this neglected global public health emergency and to mobilise efforts to control betel quid and areca nut use. In addition, future research is needed to advance our understanding of the basic biology, mechanisms, and epidemiology of betel quid and areca nut use, to advance possible prevention and cessation programmes for betel quid and areca nut users, and to design evidence-based screening and early diagnosis programmes to address the growing burden of cancers that are associated with use.