We assessed the prevalence of headache and psychosocial stress in a group of patients with cerebral ischemia and evaluated hemostatic function in these patients. Headache and preceding psychosocial stress were present in one-third and one-half, respectively, of patients capable of providing an adequate history and answering a standardized psychosocial questionnaire. There were no significant differences in hematocrit, white blood cell count and differential, fibrinogen, and platelet activation peptide ß-thromboglobulin, between patients with and without headache and between high- and low-stress patients. Fibrin D-dimer (a fragment of cross-linked fibrin) was significantly lower in high-stress compared to low-stress patients. There was no association between headache and stress level. These findings make unlikely the hypothesis that headache associated with cerebral ischemia is platelet-mediated and suggest that psychosocial stress on a chronic basis is not associated with procoagulant tendencies in this population.