This study examined the relationship between HIV serostatus disclosure and adherence to antiretroviral therapy (ART). The study was conducted with 215 HIV-seropositive patients who demonstrated poor adherence (<80%) and who were in serodiscordant relationships. Participants completed self-report measures regarding HIV serostatus disclosure and reasons for missing ART doses, as well as electronic monitoring of ART adherence (MEMS caps). Overall, 19% of the sample reported missing medication doses in the last two months due to concerns regarding serostatus disclosure. Participants who reported greater serostatus disclosure to others demonstrated higher rates of adherence, and this relationship remained after controlling for other explanatory variables. The relationship between disclosure and adherence was not mediated by practical support for adherence from others. Interventions to improve ART adherence should address the role of serostatus disclosure by providing patients with skills to maintain adherence in contexts of non-disclosure and to make informed choices regarding selective disclosure.