Platelet glycoproteins are involved in pathophysiology of cerebrovascular diseases. The aim of this study was to investigate the association between the GpIIIa gene A1/A2 polymorphism and a risk of aneurysmal subarachnoid haemorrhage (SAH) in a Polish population. In a case-control study we genotyped 288 Caucasian patients with aneurysmal SAH and 457 age-, gender- and race-matched controls. The GpIIIa A1/A2 polymorphism was genotyped with RFLP technique. No difference was found in the distribution of the polymorphism between the cases and controls (cases: A1A1-201 (69.8%), A1A2-83 (28.8%) and A2A2-4 (1.4%) vs. controls: A1A1-323 (70.7%); A1A2-128 (28.0%); A2A2-6 (1.3%), P>0.05. In a multivariate analysis female gender (OR=1.950; 95%CI: 1.308-2.907), hypertension (OR=4.774; 95%CI: 3.048-7.478) and smoking (OR=2.034; 95%CI: 1.366-3.030), but not GpIIIa A1/A2 polymorphism, were independent risk factors for aneurysmal SAH. The GpIIIa A1/A2 polymorphism is not a risk factor of aneurysmal SAH in a Polish population.