The neural mechanisms underlying the influence of persuasive messages on decision making are largely unknown. We address this issue using event-related fMRI to investigate how informative messages alter risk appraisal during choice. Participants performed the Iowa Gambling Task while viewing a positively framed, negatively framed, or control message about the options. The right anterior insula correlated with improvement in choice behavior due to the positively framed but not the negatively framed message. With the positively framed message, there was increased activation proportional to message effectiveness when less-preferred options were chosen, consistent with a role in the prediction of adverse outcomes. In addition, the dorsomedial and the left dorsolateral prefrontal cortex correlated with overall decision quality, regardless of message type. The dorsomedial region mediated the relationship between the right anterior insula and decision quality with the positively framed messages. These findings suggest a network of frontal brain regions that integrate informative messages into the evaluation of options during decision making. Supplemental procedures and results for this article may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.