<p>Group sex, understood as sexual encounters involving three or more participants, constitutes an important yet understudied dimension of contemporary sexual life. Although frequently examined in relation to HIV, sexually transmitted infections (STIs), or chemsex, group sex is rarely treated as a social and sexual phenomenon in its own right. Moreover, the widespread adoption of biomedical HIV prevention strategies, particularly pre-exposure prophylaxis (PrEP), has transformed how sexual risk, intimacy, and responsibility are negotiated in collective sexual contexts. This scoping review synthesizes peer-reviewed literature published between 2011 and 2025 that examines group sex cultures and sexual health across populations, settings, and methodological approaches. The review maps dominant conceptual frameworks, study designs, and health outcomes, with particular attention to differences between gay, bisexual and other men who have sex with men (GBMSM) and non-GBMSM populations and to shifts associated with the biomedical era. Findings reveal a fragmented literature dominated by cross-sectional quantitative studies focused on GBMSM populations, while qualitative research offers richer accounts of pleasure, negotiation, and care. Across studies, group sex environments function as socially organized spaces governed by norms, infrastructures, and collective risk-management practices. While biomedical prevention has reduced HIV-related anxiety and expanded sexual possibility, bacterial STIs, stigma, and selective disclosure in healthcare settings persist. The review highlights recurring contradictions between epidemiological framings and participants’ lived experiences and argues for treating sex in the plural as a necessary analytic shift. Future research would benefit from longitudinal, event-level, and ethnographic approaches that better capture the relational and collective dimensions of sexual health.</p>