Background: Globally, adolescent sexual and reproductive health (SRH) remains a public health priority within the Sustainable Development Goals. In Mongolia, individuals aged 15-24 account for over 40% of all sexually transmitted infections (STIs), representing a significant national challenge. Current health education for adolescents focuses predominantly on biological knowledge while neglecting life skills, consent, and communication. This focus has led to a deepening “knowledge-practice gap,” increasing vulnerability to risky behaviors. Therefore, it is essential to identify the actual SRH needs of youth and evaluate the national curriculum against international Comprehensive Sexuality Education (CSE) standards. Aim: To compare and evaluate the SRH knowledge, attitudes, and practices (KAP) of university students and to identify content gaps by comparing the national curriculum with international CSE standards. Materials and Methods: An analytical case-control study was conducted among 585 students (freshmen, n=289; senior students, n=296) using random sampling. Data were collected via a structured questionnaire based on UNESCO CSE standards and the national curriculum. Statistical analysis was performed using SPSS 26.0, employing X2 and t-tests for significance (p<0.05). Content analysis was executed using a triangulation matrix. Results: Statistically significant differences were observed between the study groups in terms of age (p<0.001), marital status (p<0.001), and living environment (p<0.001), while groups were homogeneous regarding gender (p=0.183) and socio-economic status. Senior students demonstrated significantly higher levels of SRH knowledge, attitudes, and practices across all variables compared to freshmen (p<0.001). However, a profound knowledge-practice gap persists; for instance, while 70% of freshmen were aware of STI transmission routes, regular condom use was reported at only 45%. Content analysis revealed that while the national curriculum covers biological aspects well, key CSE concepts such as “Consent,” “Psychology of Relationships,” and “Digital Safety” are notably absent. Furthermore, a curriculum based on negative attitudes and “prohibitions” contributes to fear among youth regarding seeking medical assistance. Conclusion The significant knowledge-practice gap (p<0.001) among students highlights the urgent need to revise the national curriculum in alignment with international CSE standards. To mitigate risky behaviors, it is recommended to transition from information-based teaching to a competency-based “Integrated Learning Model” supported by school-hospital-family partnerships.