OBJECTIVES: While female sex workers (FSW) are nearly 14 times more likely to be living with HIV than non-FSW, less than 40% of FSW living with HIV are on antiretroviral therapy (ART). We sought to understand how the work environment influences ART access and adherence for FSW in preparation for the Siyaphambili trial. METHODS: FSW living with HIV (n=24) and key informants (n=15) were recruited to participate in semistructured in-depth interviews using maximum variation and snowball sampling, respectively. FSW were recruited on key variants including type of sex work venue, primary work time and history of ART use. Data were collected between September and November 2017 in Durban, South Africa. Interviews were audio-recorded, transcribed and translated. Data were then coded applying grounded theory in Atlas.ti. RESULTS: FSW experienced occupational barriers to adherence including work-related migration, substance use and theft of ART on the job. Fear of wage loss due to HIV disclosure to clients and brothel managers prevented some FSW from accessing ART at their clinic and taking medications while working. FSW employed coping strategies to overcome barriers including sharing ART with colleagues, carrying small supplies of ART and visiting the clinic prior to appointments for ART refills. Further, some FSW received adherence support from colleagues who were also living with HIV. CONCLUSIONS: Considering these occupational pressures on FSW and supporting positive coping strategies are important when designing and implementing HIV treatment programmes. Findings suggest strengthening social cohesion and supporting differentiated care efforts to improve HIV outcomes among FSW living with HIV.