Until recently, the global availability and consumption of opioid agonists and psychotropic medications have been below the levels needed for research to demonstrate local efficacy and to develop local evidence-based best medical practices. In addition, the global availability and use of opioid agonists and psychotropic medications have not been sufficient to implement the well documented efficacy shown for the treatment of opioid dependence that has been developed by research over the last 40 years. This strong research base has resulted in the development of evidencebased medical practices, such as Medication Assisted Treatment (MAT) for opioid dependence. The recognition of MAT as an effective medical treatment for opioid abuse and dependence has resulted in a substantial global increase in the medical use of opioid agonists and psychotropic medications to address opioid dependence. This increase is particularly evident in the initiation of new MAT programs in regions of Europe, North America, Africa, Asia and Oceania. While in other regions of the world, the medical use of opioid agonists and psychotropic medications have not substantially increased, the implementation of MAT programs have begun as part of the global effort to reduce HIV/AIDS. These HIV prevention programs have utilized MAT as an element of programs that target injection drug users to reduce their risk of both acquiring and transmitting HIV infection. Thus, this article documents the recent international expansion of the use of MAT for opioid dependence as a result of efforts to increase access and availability of evidence based treatments for opioid dependence as well as efforts to reduce the spread of infectious diseases, such as HIV/AIDS.