The present study examined the effects of initial appraisal of stimulus aversiveness and coping adequacy on subsequent evidence of stress. Results indicated that level of appraised coping efficacy had the most pronounced effect during stressor exposure and that the pattern of this effect was dependent on whether the source of the appraised coping resources was "personal" (the subject's own resources) or "environmental" (a bogus technique donated by the experimenter). In addition, information about personal resources reduced the pre- to poststressor increment in state anxiety and lessened cognitive avoidance of stressor-related stimuli. Results were discussed with respect to differential sensitivity of components of stress response to variation in environmental versus personal sources of coping efficacy, and the specific aspects of cognitive structuring associated with variation in physiological reaction (muscle tension) were noted. The importance of factors associated with appraised coping efficacy was clearly supported, but factors involving the objective (in contrast to defensive) aspects of appraised stressor potency required further investigation, and suggestions for such future research were made.