Abstract: This study employs a quantitative content analysis approach to the issue of vaccines, analyzing a total of 1,000 vaccine-related pins posted by four anti-vaccine organizations (Mercola, Natural News, Health Impact News, and GreenMedInfo) on the social media platform “Pinterest”. Pinterest was chosen as a platform to explore given the high percentage of active female users, including moms who are often responsible for family health care decisions. We focus on vaccine opponents for two reasons. First, vaccine opponents are particularly active and organized and have done an effective job leveraging social media to voice their concerns to large audiences. Second, we argue that our approach can inform the conflict resolution tactics of government agencies, such as the CDC, under the rationale that in order to deal with anti-vaccine advocacy groups it is first necessary to understand how these groups are communicating and galvanizing support among lay audiences.