Sexually transmitted infections (STIs) and HIV remain major public health challenges. In Brazil, despite progress in diagnosis and treatment through the Unified Health System (SUS), young adults continue to represent a highly vulnerable group. Data indicate low adherence to preventive measures, even among health science students. The persistence of risky sexual behaviors and limited knowledge about pre- and post-exposure prophylaxis (PrEP and PEP) suggest a gap between access to information and its practical application. This study aimed to analyze adherence to STI and HIV prevention measures among health students at a higher education institution, considering sociodemographic variables, gender identity, sexual orientation, age, and academic level, as well as theoretical knowledge on the topic.

Quantitative study conducted between February and May 2025 with 582 undergraduate health students aged 18 years or older. Data were collected through an online questionnaire and analyzed using descriptive statistics (absolute and relative frequencies).

Most participants were cisgender women (80.0%), heterosexual (70.6%), and white (84.9%). Although 83.8% were sexually active, only 30.1% reported consistent condom use, and 44.0% had never been tested for HIV or other STIs. Among sexually active students, PrEP and PEP use was low (2.6% and 3.0%, respectively). Cisgender LGBTQIA+ men and students over 25 years showed higher adherence to prophylactic measures. Risk behaviors included binge drinking (25.8%), chemsex (17.2%), and sexting (65.8%). Cisgender women more frequently used emergency contraception (46.5%) but had lower PEP use. Theoretical knowledge was unsatisfactory in 60.5% of respondents, with lower performance in Nutrition, Psychology, and Physiotherapy, and higher scores among medical students in clinical and internship years.

Despite free access through the SUS, a gap remains between knowledge and preventive practice among health science students. Low testing rates, inconsistent condom use, and underuse of PrEP and PEP reveal deficiencies in combined prevention. Higher education institutions must implement continuous and effective strategies to make academic training a tool for health promotion and professional responsibility regarding STIs and HIV.