The nature of contrast effects is equivocal. Prior research has conceptualized contrast effects as emerging from an effortful attempt to counteract the natural tendency to assimilate to relevant contextual information. Others have suggested that contrast effects can be the natural, default outcome if the context stimulus is extreme relative to the target. Even with this latter perspective, however, individuals are believed to be sufficiently aware of the contextual influence so as to be able to counteract it if so motivated. These conceptualizations call into question the extent to which contrast effects can occur automatically, without awareness. By using an opposition paradigm that pits automatic influences against conscious influences, unequivocal evidence is provided that contrast effects can occur automatically; contrast effects emerged even when the contextual information was not accessible from memory and study participants were explicitly trying to avoid the influence of contextual information. Explanations are proffered as to why evaluations driven by automatic contrast effects could be inconsistent with preference judgments. © 2005 Wiley Periodicals, Inc.