Objectives: To assess the knowledge, attitudes, sources of HIV information and behaviours related to HIV, and to explore the difference in the HIV knowledge and attitudes between genders and school years among college students in China. Design: Descriptive, cross-sectional. Setting: 475 college students from two universities in China. Method: Data were collected with a self-report questionnaire through the Internet. Results: Only 24.2 per cent of the participants were aware that HIV could be spread through infected semen, and only 10.5 per cent were aware that condoms would decrease the risk of HIV transmission. The major sources of HIV information were through the mass media (i.e. 69.5 per cent Internet, 65.9 per cent newspaper and magazines, 58.3 per cent television). Only 17.9 per cent reported ever having had sex, and only 21.2 per cent used condoms during each sexual encounter. Females were more likely to obtain HIV information from school teachers (OR = 2.24, 95 per cent CI: 1.53-3.28, p = 0.000) and health professionals (OR = 1.95, 95 per cent CI: 1.27-2.99, p = 0.002) than males. Males were more likely to discuss sexually transmitted infections through online chat or email with strangers (OR = 0.46, 95 per cent CI: 0.29-0.71, p = 0.001). Higher school grade was associated with better HIV knowledge in this study, with graduate students, seniors, and sophomores having higher scores on HIV knowledge and HIV transmission myth subscales than freshman. Conclusion: Low rates of condom use and insufficient knowledge on HIV prevention among college students in China remain a significant problem. This research provides additional insights that may be used to develop effective HIV prevention strategies in China. (Contains 6 tables.)