SUMMARY/ABSTRACT Sexual minority men (SMM) experience intimate partner violence (IPV) at alarming rates. Prior work has linked IPV to sexual risk-taking behavior and increased risk for HIV seroconversion among SMM, but less is known about the impact of IPV on HIV and sexually transmitted infection (STI) testing/acquisition, pre-exposure prophylaxis (PrEP) uptake, and the persistence of PrEP use among SMM. While these findings reveal the potential for IPV to have a strong deleterious effect on HIV prevention, experiences of IPV are so varied among SMM (e.g., frequency, severity; steady vs. casual partnerships; mutual perpetration vs. only perpetrating or receiving violence; sexual vs. physical vs. psychological violence) that additional research is needed to unpack the overall association between IPV and HIV risk before effective interventions can be developed. Guided by a framework that combines the Syndemics and Minority Stress theories, the proposed innovative observational cohort study will examine how perpetration and/or receipt of various forms of IPV (e.g., physical, sexual, and psychological; in the context of steady or casual intimate relationships) contribute to HIV risk and protective behaviors among HIV-negative SMM over a 24-month timeframe in order to: 1. Examine the longitudinal associations of IPV with HIV testing, PrEP uptake, PrEP persistence, STI diagnosis, condomless anal sex, and HIV seroconversion. 2. Determine the structural- and individual-level and resilience and risk factors that may buffer or amplify associations between IPV and these HIV risk and protective behaviors. 3. Identify the characteristics of SMM, their intimate partners, and the relationship dynamics that serve to mediate the impact of IPV on HIV risk and protective behaviors. 4. Make recommendations for interventions that interrupt the pathways between IPV and HIV risk based on quantitative data from the cohort, and qualitative data guided by technical experts. We will assess sexual risk behavior, conduct HIV and STI testing, and assess PrEP uptake and persistence over the 24 months of follow-up. We hypothesize that greater frequency of IPV will be associated with history of childhood abuse, mental health problems, substance use, sexual risk taking and lower levels of HIV testing, PrEP uptake, and PrEP persistence. We anticipate that alcohol and substance use among participants and their partners will be highly associated with episodes of IPV (both victimization and perpetration) and with HIV risk behavior. We also hypothesize that coping skills and social support will mediate the effects of IPV on risk behavior, HIV testing, PrEP uptake, and PrEP persistence. The proposed study will advance our understanding of both the risk and resiliency factors relevant to preventing and reducing IPV, reducing IPV-associated risk behaviors, and increasing HIV protective behaviors among SMM. This research will inform the development and adaptation of IPV, HIV, and substan...