With entry of the human immunodeficiency virus (HIV) into the body begins the development of HIV disease. The HIV virus is transmitted by various body fluids such as blood, semen, breast milk and others. HIV disease gradually damages the immune system and in the final stage of the disease an acquired immunodeficiency syndrome or AIDS develops which is manifested by various opportunistic infections. The survey questionnaire examined students’ knowledge about the HIV virus and AIDS. The study involved 52 students from the Department of Biology and 46 students from the Faculty of Education, Josip Juraj Strossmayer University in Osijek. The total number of correct answers of students of the Department of Biology was statistically significantly higher compared to students of the Faculty of Education. Students of the Department of Biology showed better knowledge of the structure of the virus and its characteristics compared to the students od Faculty of Education and the existence of differences in knowledge about certain ways of transmission and prevention of infection has been established. For some questions, the total share of correct answers among all respondents was low, which indicates the need for additional education of students of both higher education institutions on HIV and AIDS.