The introduction of combination antiretroviral therapy (ART) has resulted in striking reductions in HIV-related mortality. Despite increased availability of ART and expanded coverage of ART, yet, many challenges are confronting the program. Adherence to ART regimens has been found to be the most important determinate of the success of ART. On the other hand food and nutrition security prerequisite for achieving any adherence at all. The purpose of this study was determine the food and nutrition security associated with adherence to Antiretroviral (ART) Drug therapy in PLWHA who were receiving Antiretroviral therapy (ART) in Addis Ababa, in 2012. food and nutrition security was significantly associated with adherence to ART while wholly water and opportunity infection associated with non -adherence. Designing and implementing food and nutrition program which will enhance adherence to ART and opportunity infection and wholly water will be crucial to improve adherence rate.