Aim. Excessive activation and platelet aggregation play important roles in the aetiopathogenesis of cerebral ischaemia. The aim of this study was to assess the relationship between platelet reactivity, gender and vascular risk factors in cerebral ischaemia patients.Clinical rationale for the study. The research is useful because we found high risk groups of inefficient aspirin treatment in cerebral ischaemia patients.Material and methods. The study involved 101 patients, including 69 patients with ischaemic stroke and 32 patients with transient ischaemic attack. The assessment of platelet reactivity was made within 24 hours of the disease onset using two aggregometric methods: impedance and optical.Results. Resistance to acetylsalicylic aci...