Presented in the article are the results of studying antiaggregate activity of acetylsalicylic acid and clopidogrel in a total of 36 patients suffering from various-severity chronic arterial insufficiency of lower limbs on the background of atherosclerosis obliterans. The study was conducted prior to treatment for correct selection of a particular antiplatelet agent. The obtained results showed that clopidogrel was not always more efficient than acetylsalicylic acid, since there is individual sensitivity of each patients to a particular antiplatelet agent. Therefore, an individual approach is necessary to conservative therapy of arterial insufficiency of lower limbs. For some patients it is preferable to administer clopidogrel, for others - acetylsalicylic acid. In a series of cases combined treatment is justified, while some patients having low sensitivity to both acetylsalicylic acid and clopidogrel require careful selection of alternative agents influencing other thrombocyte receptors.