This study investigated the perceptual/cognitive abnormality model of hypochondriasis, which suggests that hypochondriacal patients amplify and misinterpret normal bodily sensations. The hypothesis was evaluated by assessing pain perception and stress reactivity in female hypochondriacal (N = 15) and female nonhypochondriacal control subjects (N = 15). Subjects completed self-report measures and participated in a laboratory stress reactivity assessment consisting of the cold pressor task and an imagery task. Hypochondriacal subjects exhibited a significant increase in heart rate during the cold pressor task and a significant drop in hand temperature relative to controls. Hand temperature remained lower among the hypochondriacal subjects after the cold pressor task was terminated. Hypochondriacal subjects terminated the cold pressor task more frequently, left their feet in the cold water bath a significantly shorter period of time, and rated the cold pressor task as significantly more unpleasant (although not more intense) relative to controls. Group differences were not observed in the imagery task. Of interest, hypochondriacal subjects' baseline heart rate was significantly lower than that of controls. Taken together, these data suggest that hypochondriacal behavior may be mediated, in part, by objective differences in physiological reactivity.