Alcohol consumption and heavy drinking in young adults have been key concerns for public health. Alcohol marketing is an important factor in contributing to negative outcomes. The rapid growth in the use of new social networking technologies raises new issues regarding alcohol marketing, as well as potential impacts on alcohol cultures more generally. Young people, for example, routinely tell and re-tell drinking stories online, share images depicting drinking, and are exposed to often intensive and novel forms of alcohol marketing. In this paper, we critically review the research literature on (a) social networking technologies and alcohol marketing and (b) online alcohol content on social networks, and then consider implications for public health knowledge and research. We conclude that social networking systems are positive and pleasurable for young people, but are likely to contribute to pro-alcohol environments and encourage drinking. However, currently research is preliminary and descriptive, and we need innovative methods and detailed in-depth studies to gain greater understanding of young people's mediated drinking cultures and commercial alcohol promotion.