The administration of psychologically provocative research instruments could serve as a transient source of stress and spuriously affect results. To determine whether the administration of selected psychosocial instruments activates the stress response, we examined the physiological stress response of stable patients post-myocardial infarction (MI) to completing the Beck Depression Inventory, the Illness Perception Questionnaire, and the Spielberger State Anxiety Inventory 24 to 48 hours post-acute event. Salivary cortisol, heart rate variability (HRV), heart rate, and mean arterial pressure (MAP) were measured prior to instrument administration and 30 minutes after as indicators of the stress response. Twenty-four subjects (16 men) completed the study. Mean baseline measures of salivary cortisol (0.558 mcg/dL), heart rate (86 bpm), and MAP (86 mm Hg) were within normal ranges. A repeated-measures analysis of variance demonstrated no significant difference in salivary cortisol, F(1, 23) = 2.59, NS; HRV, F(1, 18) = 0.27, NS; heart rate, F(1, 23) = 4.29, NS; or MAP, F(1, 22) = 0.859, NS, from preinterview to postinterview. These results suggest that completing these selected psychological instruments in thefirst 24 to 48 hoursfollowing MI was not a stressful event, at least for those who were stable post-percutaneous transluminal coronary angioplasty.