Government departments and non-profit organizations often place messages about health, environment, and community involvement in the form of public service advertising in the Out-of-Home medium. Subway is the most important advertising medium with over 3.4 million daily passengers.  An online survey was conducted to examine the awareness of public service advertisements and respondents’ attitudes toward subway advertising in general and attitudes toward public service advertising. A quota sample of 100 Hong Kong people aged 18 to 69 were asked to report their awareness of ten public advertisements and their responses to statements about the attitude toward public service advertising. Results found that advertising awareness ranged from 11 to 70 percent with an average of 40.9 percent. The advertisement with the highest awareness was about green burial. The advertisement with the lowest awareness was about a transition housing project. In general, respondents demonstrated a negative attitude toward public service advertising.  They did not pay attention to government advertisements about health or environment. They did not perceive that the advertisements placed by government is easy to understand.