In the debates surrounding biotechnology and genetically modified (GM) food, data from consumer polls are often presented as evidence for precaution and labeling. But, how much do consumers actually know about the issue? New data collected from a nationwide U.S. survey reveals low levels of knowledge and numerous misperceptions about GM food. Nearly equal numbers of consumers prefer mandatory labeling of foods containing DNA as do those preferring mandatory labeling of GM foods. When given the option, the majority of consumers prefer that decisions about GM food be taken out of their hands and be made by experts. After answering a list of questions testing objective knowledge of GM food, subjective, self-reported knowledge declines somewhat and beliefs about GM food safety increases slightly. Results suggest consumers think they know more than they actually do about GM food, and queries about GM facts cause respondents to re-assess how much they know. The findings question the usefulness of results from opinion polls as motivation for public policy surrounding GM food.