Objective: To evaluate a WeChat-based HIV and AIDS educational intervention to enhance knowledge, improve attitudes and reduce stigma among college students in China. Design: Randomised controlled trial. Setting: Public research university in China. Method: A total of 111 college students were randomly assigned to either an intervention group or a control group. Participants in the intervention group received an enhanced HIV and AIDS education course delivered via WeChat for 8 weeks. Independent-samples "t"-tests were used to analyse changes in HIV-related knowledge, attitudes and stigma. Results: Findings showed that both HIV- and AIDS-related knowledge (p<0.001) and attitudes (p<0.001) significantly changed in the intervention group. The intervention group also demonstrated lower stigma scores on 'moral judgment' (p<0.001), 'personal stigma' (p=0.01), 'perceived community stigma' (p<0.001) and the 'total stigma scale' (p<0.001). Conclusion: Results show that college students in China may benefit from a technology-based intervention which could potentially be integrated into routine HIV education for college students.