The present study seeks to understand how social comparison information may be used to provide individuals with information about their level of risk and to promote health behavior. The effect of peer comparison information, presented alone or in the context of expert recommendations, was examined across two studies using distinct experimental manipulations. Study 1 showed that regardless of whether expert standards were available or not, participants who were provided with inflated estimates of peer flossing behavior demonstrated increased behavioral intentions and increased flossing behavior measured 3 months later. This pattern was replicated in Study 2 with effects on attitudes toward flossing and intentions to floss. These findings add to a growing literature identifying comparative feedback as distinct from objective information and are discussed in terms of implications for health promotion and risk communication. Copyright © 2009 John Wiley & Sons, Ltd.