Platelet activation is a complex process in which platelet reorganization takes place associated with changes in the cell shape, topology, membrane elasticity and microparticle production. The aim of this study was to investigate the changes/aberrations in the platelet activity, elasticity and morphology in healthy subjects, carriers of A allele of prothrombin G20210A polymorphism. Blood samples from 18 healthy subjects were used for platelet analysis by force-mode atomic force microscopy. Restriction analysis was used to investigate the carriage of G20210A polymorphism in the prothrombin gene. Flow- cytometry was applied to evaluate platelet activation. Young’s modulus of the plasma membranes of platelets derived from healthy subjects, carriers of variant A allele of prothrombin 20210G>A polymorphism (407±69 kPa) is two times higher than the one determined for noncarriers (195.4±48.7 kPa; p<0.05). The background activity of platelets measured as an interrelation of Cd41/Cd61 and CD62 by flow cytometry was also higher in carriers of variant A allele of prothrombin 20210G>A polymorphism (5.0%) than in non-carriers (1.3%). Platelets isolated from healthy carriers of variant A allele of prothrombin 20210G>A polymorphism exhibited a higher level of activity and a higher degree of stiffness at the stage of spreading as compared to platelets from noncarriers.