To date, more than 19 million people have died from AIDS and nearly 40 million are HIV positive. Behaviour change communication campaigns have been implemented, with varying degrees of success, to initiate and sustain proactive behaviour among target groups at risk of HIV. The efficacy of these campaigns may be enhanced by focusing on behavioural determinants including recipient knowledge and attitudes about HIV/AIDS, as well as perceptions of personal risk. This study therefore examines a pilot programme designed to assess the utility of using ambient media to influence young adults’ intentions to engage in proactive HIV/AIDS prevention strategies. Ambient media, in the form of washroom posters, were used in high-risk settings such as Indonesian bars and cafés. Results indicated individuals exposed to the ambient washroom poster were more likely to report AIDS messages had strongly influenced them to change their lifestyle in order to minimise infection risk and to use condoms as a means of reducing their infection risk. A comparison of ‘high risk’ intervention and control cases revealed those exposed to the washroom poster were more likely to acknowledge they were at personal risk of AIDS. Future research needs to examine the degree to which reflective mirrors embedded in posters enhance message personalisation. A number of other findings are important to note. Knowledge of transmission vectors appeared variable, with some modes being better understood than others.