This field experiment focused on perceived public opinion about the use of primates in laboratory research. We used this contentious issue to examine the simultaneous effects of three hypothetical ideas-the hostile media perception, the persuasive press inference, and the projection bias-on partisan perceptions of public opinion. Our data supported the projection hypothesis but also confirmed that partisans on each side of the issue judged news articles to be biased in a disagreeable direction relative to judgments of those on the other side. The perception of relatively disagreeable media bias, in turn, influenced perceptions of public opinion. Results supported the hypothesis that people make inferences about the climate of opinion based on their reading of the news, especially the perceived slant of that news.