A literature review of original research articles on adherence to antiretroviral therapy (ART) in developed countries, covering January 2000 to June 2011, was conducted to determine if gender differences exist in the prevalence of nonadherence to ART. Of the 1,255 articles reviewed, only 189 included data on the proportion of the study population that was adherent and only 57 (30.2%) of these reported proportional adherence values by gender. While comparing articles was challenging because of varied reporting strategies, women generally exhibit poorer adherence than men. Thirty of the 44 articles (68.2%) that reported comparative data on adherence by gender found women to be less adherent than men. Ten articles (17.5%) reported significant differences in proportional adherence by gender, nine of which showed women to be less adherent than men. These findings suggest that in multiple studies from developed countries, female gender often predicts lower adherence. The unique circumstances of HIV-positive women require specialized care to increase adherence to ART.