Advances in the diagnosis and treatment of HIV disease have resulted in increased survival for HIV-infected patients. Strict adherence to antiretroviral therapy is required to obtain these benefits, however. This holds true for older patients who often are diagnosed later in their disease course and who have shorter survival periods than younger patients. Although there have been few studies of antiretroviral adherence in older HIV patients, this article reviews the literature regarding antiretroviral adherence in younger HIV-infected adults as well as studies of medication adherence in older patients with other disease states. It then discusses the application of adherence interventions in these other populations to older HIV-infected adults. Several methods have been used in measuring antiretroviral adherence, including electronic monitoring, self-report, pill counts, viral load, therapeutic drug monitoring, and several other techniques. The advantages and disadvantages of these methods also are presented as well as recommendations for future adherence research in older HIV-infected adults. Finally, this article details areas of unmet research need concerning HIV medication adherence in older adults.