The purpose of this study was to examine the association between institution-delivered sex education given under real-world conditions and sexually transmitted infection (STI) rates, STI fatalism, and prior STI testing among African American men aged 15-24 who have sex with women. Participants were tested at community venues for Chlamydia and gonorrhoea and undertook a survey to elicit history of sex education and sexual health information. Among 1196 participants, 73.0% reported having received institution-delivered sex education topics including STI information (90.5%), condoms (89.2%), pregnancy/birth (72.1%) and birth control (67.1%). Among a subset of participants asked about the quality of sex education, 85.7% reported it was 'very good' or 'OK'. The prevalence rate for Chlamydia and/or gonorrhoea was 10.5%. Those who received sex education were more likely to have lower STI fatalism (51.0% vs. 42.4%, p = 0.01) and more likely to report previous Chlamydia screening (44.1% vs. 31.6%, p < 0.01), but did not have a significantly lower rate of Chlamydia and/or gonorrhoea (9.9% vs. 12.4%, p = 0.20) compared to those who did not receive sex education. These findings suggest that institution-delivered sex education given under real-world conditions has beneficial effects on STI risk factors among young African American men.