The aim of the study was the investigation of clinical data and platelet haemostasis parameters in patients with atherothrombotic stroke for secondary prophylaxis improvement. Materials and Methods. 41 patient: 26 (63,4%) males, 15 (36,6%) females, mean age 66,0±9,4 years and 18 healthy person were examined. Neurological examination was performed, patient condition was estimated with National Institute of Health Stroke Scale and Rankin scale. The set of investigation included clinical blood analysis, adenosinediphosphate-induced agregometry, flow-cytometry, molecular genetic analysis of gene Iba. Results. There was platelet activation in patients with atherothrombotic stroke according to flow-cytometry data. The conventional optic agregometry was not helpful for revealing of platelet activation. The expression of 1ba receptors correlated with the point of National Institute of Health Stroke Scale at discharge. The incidence of Iba gene mutation was higher in patients with atherothrombotic stroke comparing with control group. Conclusions. The revealed data predispose to the possibility of individual administration of antiagregant therapy in such patients.