Sexual behaviour remains the primary target of AIDS prevention efforts worldwide, it is one kind of human behaviour that continues to affect youths world wide. Despite government efforts and NGOs effort’s to address HIV/AIDS, youths continue to be affected disproportionally. Understanding the socio-cultural context in which sexual behaviour occurs will help to protect youth from HIV/AIDS. The general objective of this study was to determine the level of knowledge, attitude and sexual behaviour of university students concerning HIV/AIDS in order to provide necessary information to university authorities and assist policy makers to design more relevant and efficient programmes to combat HIV/AIDS specifically targeting university students. The study adopted a cross sectional design using closed ended self administered questionnaires from a sample of 360 students in two public universities. The Statistical Package for Social Sciences (SPSS) version 11.5 was used to analyse the data. Descriptive statistics and index scales were used to gauge levels of risky sexual behaviour, misconception on means of HIV/AIDS transmission, attitude and barriers to sexual behavioural change. F-test was used to test the hypotheses at 5% level of significance. The key findings indicate that students’ sexual behaviour was influenced by demographic characteristics such as age, living arrangement, marital status, university of study and entrance status (P<0.05). Risk of sexual behaviour increased with student’s age up to 35-39 age group and girls were at more risk than boys. Levels of knowledge about HIV/AIDS were found to be high. However, misconception was widespread. Sexual behaviour was not associated with attitude towards HIV/AIDS and perceived barriers to sexual behavioural change. The study recommends the government and universities to develop policies, programmes and strategies to address sexual behaviours. In addition, peer-based interventions should be increased to ensure that university students have access to accurate information on HIV/AIDS.