In countries severely affected by HIV/AIDS, shortages of health workers present a major obstacle to scaling up HIV services. Adopting a task shifting approach for the deployment of community health workers (CHWs) represents one strategy for rapid expansion of the health workforce. This study aimed to evaluate the contribution of CHWs with a focus on identifying the critical elements of an enabling environment that can ensure they provide quality services in a manner that is sustainable. The method of work included a collection of primary data in five countries: Brazil, Ethiopia, Malawi, Namibia, and Uganda. The findings show that delegation of specific tasks to cadres of CHWs with limited training can increase access to HIV services, particularly in rural areas and among underserved communities, and can improve the quality of care for HIV. There is also evidence that CHWs can make a significant contribution to the delivery of a wide range of other health services. The findings also show that certain conditions must be observed if CHWs are to contribute to well-functioning and sustainable service delivery. These conditions involve adequate systems integration with significant attention to: political will and commitment; collaborative planning; definition of scope of practice; selection and educational requirements; registration, licensure and certification; recruitment and deployment; adequate and sustainable remuneration; mentoring and supervision including referral system; career path and continuous education; performance evaluation; supply of equipment and commodities. The study concludes that, where there is the necessary support, the potential contribution of CHWs can be optimized and represents a valuable addition to the urgent expansion of human resources for health, and to universal coverage of HIV services.