Adherence is key to successful antiretroviral therapy (ART). Many countries with increased HIV prevalence and the greatest need for ART have limited health resources. Recent assumptions that the adherence required for successful ART will not be achieved in resource-poor settings have led to calls for caution in expanded access programs. New studies from Africa refute this, showing excellent adherence and virologic outcomes. Major factors contributing to adherence or nonadherence are whether the drug is accessed for free or is self-funded, patient preparedness for use of ART, stigmatization related to being HIV-positive, and ease of use of regimen.