Subjects estimated the intensity of various concentrations of an odorant (ethyl butyrate), a tastant (sodium saccharin), and mixtures of the two. The question of primary interest was whether the perceived intensity of the odor-tast mixtures would be equal to, greater than , or less than the intensities of the unmixed components. The outcome approximated simple additivity: The intensity of the mixtures was only slightly less than the sum of the perceived intensities of the unmixed components. An examination of how subjects apportioned their judgments into the categories odor and taste revealed the existence of taste-smell confusions. Subjects ascribed little odor magnitude to solutions containing only sodium saccharin, but ascribed considerable taste magnitude to solutions containing only ethyl butyrate. The taste ascribed to ethyl butyrate was not due exclusively to its action on gustation since, when the nostrils were closed, as much as 80% of the "taste" disappeared. Subjects seem to resolve ambiguity regarding the locus of mutual olfactory-taste stimulation in favor of taste.