Public opinion often diverges widely from reality on the size and makeup of immigrant populations but prior research has not established whether the media has any causal role in the construction of these perceptions. This paper examines how actually-occurring media portrayals of immigrants in Britain—drawn from recent large-scale quantitative studies of the British national press—affect attitudes toward and perceptions of immigrants among members of the British public. We report on an original survey experiment that tests the impact of various news frames. Several outcomes are measured including the individual’s estimates of the size of the immigrant group, perceptions of who immigrants are, and immigration policy preferences. We find support for the notion that even subtle coaxing can shift public conceptions of immigration, in this case toward more realistic understandings of the overall size and make-up of the immigrant population in Britain. The implications for the link between media frames and public opinion arising from these findings are discussed.