Background: Sexual violence is a serious violation of human rights that mainly affects women. Among the impacts on health, sexually transmitted infections (STIs) are important due to their high prevalence and possible reproductive harm. Objective: To check and compare the incidence of STIs in adolescent and adult women victims of sexual violence. Method: Retrospective cohort study with 135 adolescents (10-19 years) and 154 adult women (≥20 years) attending the Pérola Byington Hospital, São Paulo, Brazil, with vaginal and/or anal unprotected exposure during the sexual crime, with ingression between 72 hours and 10 days of the violence, who did not receive prophylaxis for STIs, hepatitis B or HIV. Cases with earlier STIs, pregnant women and violence from an intimate partner were excluded. The outcome was the occurrence of STIs in the two groups. Data were introduced in the program Epi Info6, version 6.04b, with statistical analysis by chi-square test. Results: The diagnosis of STIs occurred for 32.6% of adolescents and 31.1% of adult women. The median age was 21.0±5.8 years. Adolescents were more vulnerable to the related and known aggressors. Ninety-two patients with STIs (31.8%) were found along with 120 infections among the 289 women, distributed between HPV (16.9%), trichomoniasis (6.6%), chlamydia (3.8%), herpes (2.4%), hepatitis B (2.4%), syphilis (2.1%), gonorrhea (1.7%) pelvic inflammatory disease (1.7%), hepatitis C (1.4%), HIV (1.4%) and HTLV I and II (1.0%). Conclusion: The incidence and distribution of STIs show no differences in the two groups, suggesting similar risk for adolescent and adult women when submitted to the same forms of exposure during sexual crime.