Vulnerable populations are at increased risk for HIV/AIDS, especially adolescent men who have sex with men (AMSM) and adolescent travestis and transgender women (ATGW). Pre-exposure prophylaxis (PrEP) is one component of combination HIV prevention and is already available for these populations in Brazil. However, ensuring its uptake entails certain challenges since inequality and barriers have traditionally marked access and linkage to the related public health services. Peer navigation could be a way of mediating the linkage process because it involves peers keeping track of others’ care schedules, dynamically fostering linkage to care according to the needs of users and the actors involved in their everyday care contexts. Therefore, this study proposes analyzing peer-navigator-mediated linkage to PrEP care for 15- to 19-year-old MSM and transgender women from the PrEP1519 project in Salvador, Bahia State, Brazil. In total, 15 field notebooks/diaries, written in April-July 2019, by four peer navigators were analyzed, as were the transcripts of one focal group and 20 semi-structured interviews with adolescents (17 MSM and three trans women) between June and December 2019. Linkage via peer navigator and participant is influenced by emotional dynamics and shared personal characteristics. It is fluid and unstable and calls for care practices to be shaped to meet each participant’s needs. For peer navigation to be adopted as a care strategy for sexually transmitted infection prevention and treatment, it should envisage not only increased linkage to care but also sensitivity to service users’ specific characteristics and lived experiences.