This research provides secondary data analysis of two large-scale scientist surveys. These include a 2009 survey of American Association for the Advancement of Science (AAAS) members and a 2006 survey of university scientists by the United Kingdom’s Royal Society. Multivariate models are applied to better understand the motivations, beliefs, and conditions that promote scientists’ involvement in communication with the public and the news media. In terms of demographics, scientists who have reached mid-career status are more likely than their peers to engage in outreach, though even after controlling for career stage, chemists are less likely than other scientists to do so. In terms of perceptions and motivations, a deficit model view that a lack of public knowledge is harmful, a personal commitment to the public good, and feelings of personal efficacy and professional obligation are among the strongest predictors of seeing outreach as important and in participating in engagement activities.