Studies worldwide has reported that HIV/AIDS remains a prominent health issue concerning adolescent sexual behaviors. Literature shows that early initiators of sex are less knowledgeable and inexperienced, some have adequate knowledge but risky sexual practices still continue to flourish despite adequate campaign on its prevention, it still fails to translate into practice. The study aimed to to evaluate the degree of knowledge and behavior of tertiary school students towards HIV/AIDS. Moreover, it was conducted due to the behavior and practices of youths who are engaging in risky sexual behaviors without any protection, lack of basic knowledge, and the reluctance of adults in discussing reproductive health. The Health Belief and Health Promotion Model was provided as frameworks. Simple stratified random sampling recruited five hundred (500) students ages 15-24 from different tertiary schools of Ormoc City, Leyte. Data were collected using 39-item researcher structured questionnaire where 21 questions intended to measure their degree of knowledge and 18 were intended to measure the degree of behavior. A descriptive statistics forged the analysis and interpretation of the results. The findings revealed that despite the respondent?s level of knowledge (3.19) and behavior (2.96) towards HIV/AIDS, some 34.2% young adults still continue to harbor myths and misconception like mosquitoes are the most common vector of the infection. It is recommended that sustainable comprehensive education on the benefits of having comprehensive knowledge about the infection be put in place. Moreover, it is recommended to establish meaningful health strategies so that the young adults develop their competence and ability to execute a health promoting behavior.