Aims. To provide an overview of the availability of pharmaceutical opioids and the evidence on the extent of diversion and injection in South Asia. Methods. This paper reviews existing peer-reviewed and 'grey' literature on the extramedical use and injection of pharmaceutical opioids in Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka. Results. Reports indicate that prescribing for all types of pain is inadequate. There is a paucity of empirical data across South Asia regarding the mechanisms and extent of the diversion and misuse of pharmaceutical opioids, although the problem is widely acknowledged. India is believed to account for significant large-scale diversion within the region and further afield through poor regulation of licit opioid production and pharmacies. A recent decline in use of natural opiates has been accompanied by an increase in pharmaceutical opioid misuse and increasingly, injection, particularly in Bangladesh, India, Nepal and Pakistan. The medications are typically buprenorphine preparations and/or other lower potency opioids, such as codeine, nalbuphine and dextropropoxyphene. Opioid substitution treatment and needle-syringe programs are available in some countries, but better coverage is needed. Studies identify a lack of comprehensive knowledge regarding HIV and high prevalence of risk behaviours among at-risk populations in the region. Conclusions. It is imperative for the region to rapidly facilitate access to opioids for the treatment of pain and opioid dependence, ensuring effective systems that maintain quality care, regulate and monitor retail pharmacies, and minimise diversion. Prevention of HIV among people who inject pharmaceutical opioids is essential.[Larance B, Ambekar A, Azim T, Murthy P, Panda S, Degenhardt L, Mathers B. The availability, diversion and injection of pharmaceutical opioids in South Asia. Drug Alcohol Rev 2011;30:246-254] �� 2011 Australasian Professional Society on Alcohol and other Drugs.