Background: Human Immunodeficiency Virus (HIV) is a virus that infects or damages cells of the immune system, so that it can cause progressive damage. Acquired immunodeficiency syndrome (AIDS) is the next stage of HIV infection. AIDS is a chronic condition that has the potential to threaten a person's life caused by HIV. HIV is a major health problem globally. HIV AIDS is highest in the age range of 20-29 years. According to the Ministry of Health (2018), the percentage of HIV in the 20-24 years age group is 16.7% and AIDS in the 20-29 years age group is 29.5%. Adolescent and adult groups are productive age groups (15-24 years), and have a great sense of curiosity, dare to bear the risk of actions carried out without precedence by careful consideration. Lack of knowledge about reproductive health such as free sex can cause premarital sex acts so that a lot of incidents of pregnancy outside marriage. Therefore the importance of education about reproductive health issues so as not to cause reproductive health problems such as HIV / AIDS. Pornography can also make someone fall into promiscuity where negative thoughts and actions to engage in premarital sex will arise. Aim: to find out the description of students' knowledge about HIV / AIDS at one of the Indonesian Private Universities in the West. Method: This research uses descriptive quantitative method. The samples of the study were 286 students at the Private University of Indonesia. The sampling technique uses purposive sampling. The instrument in the study used a questionnaire. test results Validity and reliability with the results of r count 0.361-0.659 and Cronbach's alpha 0.704. Results showed that students who had a good level of knowledge were 187 respondents (65.4%), students who had an enough level of knowledge were 71 respondents (24.8%), and students who had a less level of knowledge were 28 respondents (9.8%).