The coagulative system has an important role on haemodialysis and on atherosclerosis genesis; in particular the platelets are key elements of the coagulation and of atherosclerosis phenomena. Alterations of the coagulative system and increase risk of developing atherosclerosis are reported in the aging. We in this paper, report the results obtained studying the influence of the interaction between the elderly and dyslipidemia on the coagulative system in haemodialyzed patients. The obtained data showed that the hypertriglyceridaemia in interaction with the elderly accelerates and increases platelet aggregation after stimulation by ADP, Epinephrine and Collagen. So, it is important to consider hypertriglyceridaemia and age as thrombogenic factors and atherosclerosis accelerating factors in haemodialyzed patients.