India's National AIDS Control Organization (NACO) provides free first-line antiretroviral treatment (ART) at government centers for people living with HIV. To assist in developing policies and programs to ensure equity in ART access, we explored barriers to ART access among female sex workers (FSWs) living with HIV in Chennai. Between August and November 2007, we conducted three focus group discussions and two key informant interviews. Data were explored using framework analysis to identify categories and derive themes. We found interrelated barriers at the family=social, health care system=programmatic, and individual levels. Major barriers included fear of adverse consequences of disclosure of HIV status due to stigma and discrimination associated with HIV and sex work, lack of family support, negative experiences with health care providers, lack of adequate counseling services at government centers and by outreach workers employed by nongovernmental organizations (NGOs), perceived biased treatment of FSWs who are not referred by NGOs, lack of adequate knowledge about ART, and fatalism. Barriers can be addressed by: creating effective measures to reduce stigma associated with HIV=AIDS and sex work at the familial, societal, and health care system levels; incorporating information about ART into targeted interventions among FSWs; training counselors at government hospitals and NGO outreach workers on treatment issues; improving infrastructure and staffing levels at government centers to allow adequate time and privacy for counseling; and implementing government mass media campaigns on ART availability. Finally, it is crucial that NACO begin monitoring ART coverage of FSWs and other marginalized populations to ensure equitable ART access.