Purpose South African children have high HIV risk yet few prevention interventions are effective. group sessions for RKI-1447 parents of youth aged 11-15. Sixty-six parents [64% female] and their 64 adolescents [41% female] completed surveys before and 1-2 weeks post-intervention; surveys assessed comfort with talking about sex communication about 16 HIV- and sex-related topics and parents’ condom use self-efficacy and behavior. Thirty-four Black-African (Xhosa-language) and 32 Coloured (mixed-race; Afrikaans-language) parent-child dyads participated. Parents were randomized to intervention (n=34) and control (n=32) groups; randomization was stratified by language. Results Multivariate regressions indicated that the intervention significantly increased parents’ comfort with talking to their adolescent about sex b(SE)=0.98(0.39) p=0.02 and the number of sex- and HIV-related topics discussed with their adolescent b(SE)=3.26(1.12) p=0.005. Compared to control parents intervention SCC1 parents were more likely to discuss new sex- and HIV-related topics not discussed before the intervention b(SE)=2.85(0.80) p<.001. The intervention significantly increased parents’ RKI-1447 self-efficacy for condom use b(SE)=0.60(0.21) p=0.007. Conclusions holds promise for improving parent-child communication a critical first step in preventing HIV among youth. a worksite-based HIV prevention program for parents could improve parent-child communication about HIV and sexual health. We hypothesized that would enhance parent-child communication including prompting more parent-child conversations about HIV and sex. We also hypothesized that the program could lead to changes in parents themselves including encouraging greater self-efficacy for condom use and greater condom use behavior. Methods Intervention Setting and Community Partnership This study was conducted in the municipal Cape Town City Council (hereafter referred to as “City”) worksites in the Western Cape province which is 27% Black African 54 Coloured and 18% White. Official City languages are English isiXhosa (spoken by the majority of Black Africans in the Western Cape) and Afrikaans (spoken by people who are Coloured). The City is Cape Town’s largest employer with a workforce of ~22 0 across multiple locations. We trained study facilitators from the City’s pool of HIV peer educators.23 Consistent with principles of community-based participatory research (CBPR) 24 the City was an engaged and equal partner throughout the research process from formative intervention development research to intervention implementation. The community-academic study team also partnered with a community advisory board (CAB) composed of worksite representatives and staff at community-based organizations that emphasized adolescent parent and/or family social services and HIV prevention. The CAB met at key points during the project to contribute to culturally relevant intervention adaptation help interpret results and provide feedback regarding intervention acceptability feasibility and sustainability. Study Design We evaluated with two intervention and two wait-list control groups of parents/caregivers (hereafter referred to as “parents”) stratified by language (Afrikaans vs. isiXhosa). Randomization was conducted following baseline assessment at the individual parent level within worksite; parents RKI-1447 entered the intervention ~one-week post-baseline. Parents and adolescents were surveyed at baseline and ~two-months post-baseline (one-to-two weeks after the end RKI-1447 of the five week-intervention). Intervention Protocol The intervention consisted of five weekly two-hour group sessions for parents of adolescents aged 11-15; each group consisted of ~15 parents. As is standard for the City’s HIV prevention programming for employees parents were released from work for RKI-1447 the sessions. The program was standardized and manualized across groups and each group was led by a trained facilitator and co-facilitator who were City peer HIV educators. Training consisted of two five-day workshops led by a doctoral-level clinical psychologist who modeled the program sessions and taught motivational interviewing principles25 (i.e. a nonconfrontational style emphasizing open-ended questions and reflective listening as well as exploration of ambivalence about communication with adolescents about sex) for facilitators to use when interacting with and teaching parents. Using formative.