Introduction Post-Exposure Prophylaxis (PEP) is the use of antiretroviral treatment (ART) to reduce the risk of HIV infection after exposure. Interventions based on ART are recommended mostly for key populations, such as people aged 15 to 24 years. This study aims to evaluate the knowledge regarding PEP amongst young university students.

Methods Cross section study carried out from August to September 2016 among Health, Education and Exact Sciences students at the State University of Bahia. Socio-epidemiological data regarding sexuality and PEP were collected through a standardised self-applied questionnaire. SPSS v20.0 was used for statistical analysis.

Results We enrolled 362 students, 85% (305/359) females, mean age of 22.9 (±4.8) years, 83.1% (301/362) self-declared non-white, 90.6% (327/361) single and 43.4% (154/355) had an income ≤2 minimum wages. As for sexual behaviour, 12.1% (19/177) have sexual intercourse with people of the same sex, 22.6% (63/279) have anal sex, 69.2% (193/279) oral sex; 34.9% (96/275) irregular condom use, including 36.2% (81/224) of Health students (p=0.36). As for the PEP, 39.3% (142/361) have heard about it, 73.6% (14/19) of the men who have sex with men had some knowledge (p<0.01; OR 4.73, 95% CI 1.67–13.45); 92.0% (332/361) did not know the time limit to start the PEP, 93.1% (335/360) did not know the duration and 68.9% (248/360) are unaware of the basic indication criteria; 87.0% (315/360) did not know the sites for administration, 0.6% (2/361) affirm to have used it and 98.3% (348/354) state to not change the sexual behaviour after PEP, some said they would begin unprotected sexual practices, of which, 83.3% (5/6) were from the Health courses.

Conclusion The results evoke the challenges regarding the implantation of new strategies for HIV prevention. The limited knowledge regarding intervention and sites that offers PEP evidences barriers to access and prevention of new infections. These findings highlights the need for disseminate knowledge on PEP among young people, thus making it effective as an HIV prevention strategy.