We adopted a simple slide test and image analysis to determine the state of erythrocyte adhesiveness/aggregation in the peripheral blood of 45 patients with acute ischemic stroke, 30 with TIA and 27 matched controls. A highly significant (P=0.005) difference was noted between patients and controls regarding the degree of erythrocyte adhesiveness/aggregation while there was no significant difference for both erythrocyte sedimentation rate or fibrinogen concentrations. We suggest that our slide test might be a low cost and real time method to detect the increased erythrocyte aggregability in the peripheral blood of patients with acute ischemic neurological events. These findings might be relevant in view of recent studies that suggest a favorable effect of therapeutic interventions directed at the improvements of this hemorrheological aspect in individuals with ischemic vascular conditions.