This paper provides evidence of substantial individual differences in the affective importance of odors, and offers initial validation for an eight-item scale of the impact of odor (AIO) on liking for people, places, foods and cosmetic/health products. In study 1, 116 American college students and 336 Flemish Belgian college students completed the AIO along with other measures of reactions to odors and to commercial products designed to mask body odors. There were substantial individual differences in AIO scores, but means were similar for males and females, and for US and Belgian respondents. Higher AIO scores were associated with more odor-mediated memory, more attention to odors and more liking or disliking for odors as a function of their association with liked and disliked persons. AIO scores were not related to preference for toiletries with artificial scents, to use of products to mask natural body odors, or to disgust sensitivity. In study 2, AIO scores were strongly related to a measure of evaluative conditioning (a form of Pavlovian associative learning) in the laboratory, using liked and disliked odors as unconditioned stimuli and pictures of faces as conditioned stimuli.