Abstract. Full text article available at https://doi.org/10.1016/j.drugpo.2016.01.012Strong evidence supports the effectiveness of methadone-assisted therapy (MAT) to treat opioid dependence, reduce the risk of HIV transmission, and improve HIV related health outcomes among people who inject drugs (PWID). HIV prevalence reaches 71% in women who inject drugs (WWID) in Dar es Salaam, Tanzania; creating an urgent need for access to MAT. Despite the availability and potential benefits of treatment, few women have enrolled in services. This formative research sought to identify programmatic strategies to increase women's participation in outreach and their subsequent enrollment in MAT. We conducted twenty-five, in-depth interviews with patients and their providers at a MAT clinic. Open-ended interviews explored enrollment experiences, with a focus on contextual barriers and facilitators unique to women. Ethnographic observations of harm reduction education at outreach sites and the MAT clinic enriched interview data. Trust/mistrust emerged as an overarching theme cross cutting patient and provider accounts of the connective process to enroll PWID in the methadone program. We explore trust and mistrust in relationship to the interrelated themes of family loss, social isolation, vehement discrimination and motivation for treatment. Narratives delineated both the generation of mistrust against PWID and the generation of mistrust in PWID against outsiders and medical institutions. In order to enroll PWID in treatment, community base organizations engaged outreach strategies to overcome mistrust and connect eligible patients to care, which varied in their success at recruiting women and men. Greater discrimination against WWID pushed them into hiding, away from outreach teams that focus on outdoor areas where men who inject drugs congregate. Building trust through multiple encounters and making a personal connection facilitated entry into care for women. Only PWID were eligible for MAT, due to resource constraints and the higher risk associated with injection drug use. Many women smoke heroin, yet still face high risk of HIV, resulting from low condom use during sex work to fund drug use. Expanding outreach times and locations, by women peers, could increase women's enrollment in treatment. Allowing women who smoke heroin to enter the program could prevent onward transmission via sex work and reduce the chance of progressing from the lower risk smoking or sniffing to injection drug use.