Uncertainty is an unavoidable part of human life. How do states of uncertainty influence the way people make decisions? We advance the proposition that states of uncertainty increase the reliance on affective inputs in judgments and decisions. In accord with this proposition, results from six studies show that the priming of uncertainty (vs. certainty) consistently increases the effects of a variety of affective inputs on consumers' judgments and decisions. Primed uncertainty is shown to amplify the effects of the pleasantness of a musical soundtrack (study 1), the attractiveness of a picture (study 2), the appeal of affective attributes (studies 3 and 4), incidental mood states (study 6), and even incidental states of disgust (study 5). Moreover, both negative and positive uncertainty increase the influence of affect in decisions (study 4). The results additionally show that the increased reliance on affective inputs under uncertainty does not necessarily come at the expense of a reliance on descriptive attribute information (studies 2 and 5), and that the increased reliance on affect under uncertainty is distinct from a general reliance on heuristic or peripheral cues (study 6).