Abstract Human papillomavirus (HPV) accounts for over 80% of anal cancer cases. In the effort to prevent HPV-related cancers, the 9-valent HPV vaccine emerged as a crucial intervention, targeting HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58; the previous 4-valent (types 6,11,16,18) and 2-valent (types 16, 18). This study involved 213 women aged 21-50 attending gynecology and colonoscopy clinics in San Juan, Puerto Rico. The study assessed anal HPV prevalence and analyzed vaccination status-related differences. Anal swabs were collected for HPV testing using the ATILA AmpFire, targeting 17 HPV types. This method identified 15 high-risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, and 68) and two low-risk HPV types (6 and 11). Prevalence of any HPV, HR-HPV, and LR-HPV, and of specific HPV types were calculated by overall and vaccination status. Differences were assessed for statistical significance (p<0.05) using Fisher's exact or Pearson χ2 test. The mean age of women was 36.0 ± 5.9 years. Overall, 19.7% (n=44) had received the HPV vaccine; among them, 52.2% (n=23) had received the 4-valent vaccine, 2.3% had received the 2-valent vaccine, 2.3% had received the 9-valent vaccine, and 43.2% were uncertain about their specific HPV vaccine type. The prevalence of anal HPV infection was 68.5% for any HPV, 61.5% for HR-HPV, and 15.0% for LR-HPV. The most prevalent HR-HPV types were HPV 56 (13.2%), HPV 68 (11.7%), and HPV 66 (11.2%). There were no statistically significant differences in the prevalence of any HPV, HR-HPV, and LR-HPV between vaccinated and unvaccinated women. The most common HR-HPV type among vaccinated were HPV 66 (20.5%), HPV 31 (18.2%), HPV 56 (15.9%), while the most common among unvaccinated women were HPV 56 (12.4%), HPV 68 (12.4%), and HPV 16 (12.4%). Additionally, when evaluating as a grouped variable, the HPV genotypes covered by the 4-valent, unvaccinated women had a significantly higher prevalence of these types as compared to those vaccinated (28.9% vs. 13.6%, respectively, p-value =.03). The unvaccinated women showed a lower prevalence for HPV types covered by the 9-valent vaccine compared to the vaccinated cohort (43.2% vs. 45.5%). However, this difference was not statistically significant. We found a high prevalence of anal HPV among these women, with lower prevalence of 4-valent and 2-valent HPV types among vaccinated women, evidencing the pivotal role of HPV vaccination. Future research should assess the 9-valent vaccine's long-term effectiveness against more HPV types. Funding: Research Centers in Minority Institutions (RCMI), University of Puerto Rico (NIMHD # 2U54MD007600-36), and CAPAC Research Training Program (NCI #R25CA240120). Citation Format: Anelisse Dominicci-Maura, Ana Patricia Ortiz, Josefina Romaguera, Filipa Godoy-Vitorino. Prevalence of anal HPV infection in women attending a gynecology and colposcopy clinic: Assessing the potential impact of HPV vaccination [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4804.