To determine whether psychological factors differentiate patients with silent versus symptomatic myocardial ischemia, a battery of psychometric tests was administered to 68 patients with positive thallium stress tests. Compared with patients who became symptomatic (n = 25), patients with silent ischemia on the treadmill (n = 24) were less often aware of cardiac and other bodily sensations (p less than 0.005) and were less avoidant of harm or pain in general (p less than 0.05). They did not differ on variables associated with symptom reporting biases. To clarify the relationship between ischemia and symptom reporting, symptomatic patients were subgrouped on the basis of anginal pain latency. Psychologically, the patients with silent ischemia were most similar to patients with the longest pain latencies and most different from those who reported angina before the onset of ST depression. The psychological profile of patients with silent ischemia during exercise testing is consistent with a reduced sensitivity to pain and other bodily sensations.