This article examines narratives about promiscuity that are emphasized by some gay and bisexual men who are themselves living with HIV. We used semi-structured interviews to assess the processes, outcomes, and meanings of HIV diagnosis among 10 young gay and bisexual men aged between 18 and 30 years old. Interviews were conducted in health service settings for the diagnosis and treatment of HIV and AIDS in Salvador, Brazil. Based on a socioculturally oriented approach, the narratives suggest that discourse about promiscuity seems to persist, or is even strengthened, in order to explain HIV infection among young gays/bisexual men and to emphasize a more restrained sexual life following HIV diagnosis. Despite the biotechnologies and biomedical advances, some difficulties and tensions also persist in the daily life of young people living with HIV. Difficulties in starting new relationships, dilemmas around responsibility for infection/transmission, fear and guilt are elements that stand out in these narratives, demonstrating that HIV discourses and practices may produce greater stigma and discrimination in current times, individualizing and blaming certain people for the infection/transmission of the virus, and marginalizing practices that do not conform to hegemonic heteronormativity.