Background: Female adolescents and young women have the highest risk of curable sexually transmitted infections (STIs) globally. Data on the prevalence of STIs among young women in Uganda are limited. In this study, we investigated the time trends and determinants of STIs among adolescent girls and young women (15-24 years) in Uganda. Methods: We estimated the percentage of women 15-24 years from three recent consecutive Uganda Demographic and Health Surveys (2006, 2011, and 2016), who reported acquiring an STI within 12 months of the studies and examined the changes over time. A pooled multivariable logistic regression was used to examine predictors of actors associated with reporting an STI were assessed using.Results: The pooled STI prevalence was 26.0%. About 22.0% of youths reported an STI in 2006. This increased to 36.3% in 2011, before declining to 23.1% in 2016. Youths aged 20-24 years reported a higher STI prevalence (27.3%) compared to young participants (23.6%). Prevalence of STIs was significantly higher among female youths with multiple total lifetime partners (adjusted odds ratio (aOR 1.6, 95% CI 1.4-1.6). Similarly, women who were sexually active in the last 4 weeks prior to the interview (aOR 1.3, 95% CI 1.1-1.6), and women affiliated to Islam (aOR 1.3, 95% CI 1.1-1.6) or other religions (aOR 1.8, 95% CI 1.1-2.9) were more likely to report an STI. Living in Northern Uganda was found protective against STIs (aOR 0.5, 95% CI 0.3-0.7).Conclusion: The prevalence of STIs was high among female youths, 15-24 years. There is a need to adopt a holistic approach to the diagnosis and management of STIs among youths, as well as the integration of STI services in daily health care systems to increase their access to sexual and reproductive health services.