Objective To systematically review the literature of factors affecting adherence to Antiretroviral treatment (ART) in Asian developing countries. Methods Database searches in Medline/Ovid, Cochrane library, CINAHL, Scopus and PsychINFO for studies published between 1996 and December 2010. The reference lists of included papers were also checked, with citation searching on key papers. Results A total of 437 studies were identified, and 18 articles met the inclusion criteria and were extracted and critically appraised, representing in 12 quantitative, four qualitative and two mixed-method studies. Twenty-two individual themes, including financial difficulties, side effects, access, stigma and discrimination, simply forgetting and being too busy, impeded adherence to ART, and 11 themes, including family support, self-efficacy and desire to live longer, facilitated adherence. Conclusion Adherence to ART varies between individuals and over time. We need to redress impeding factors while promoting factors that reinforce adherence through financial support, better accessible points for medicine refills, consulting doctors for help with side effects, social support and trusting relationships with care providers.