Background. While HIV eradication by 2030 is a goal of the World Health Organization’s Global HIV sector, certain marginalized sub-populations still lack basic HIV knowledge. Methods: We assessed HIV knowledge among 233 females and 280 males in Haiti’s Cité Soleil (N=513), using a rudimentary measure (our previous studies indicated female sexual violence victims lacked awareness that intentionally injurious, assaults by multiple assailants constituted HIV risk). STATA enabled descriptive analysis of data. Results: Inaccurate HIV knowledge in our sample evidenced by: Endorsing HIV transmission via (1) kiss on the cheek: 83%; (2) sharing drinking glass: 80%; (3) if someone sneezes/coughs on you: 81%; (4) public toilets:79%; (5) 27% had never attended an HIV prevention program. Also, 43% correctly identified abstinence as most effective HIV prevention method, 24% had been tested for HIV, 16% knew their HIV status, yet 20% rated their HIV risk as very low. Significant gender differences emerged (p<.01): 77% women vs. 39% men knew what an HIV test is, 37% women vs. 17% men had been tested. Nearly twice the proportion of men never attended an HIV program/class (41% vs. 21%). Conclusions: Despite a 10% decline in Haiti’s HIV prevalence these past three decades, basic HIV knowledge among marginalized adults should be prioritized. Concerted efforts to prevent vertical transmission of HIV may account for more women knowing what a test is, but knowledge remains inaccurate.