Circulating platelet-leukocyte aggregates (PIA) are present in patients with various diseases of the cardiovascular system and are considered as sensitive markers of platelet activation. At the same time characteristics of PLA in the circulating blood continue to be discussed in the context of the search for early markers of inflammation, which would bring us close to ability to limit the development of inflammatory response at the earliest stage. This review is devoted to analysis of studies of PLA in the context of assessment of functional activity of platelets and possibilities of cooperation of blood cells during activation of leukocytes at early stage of realization of inflammation process. Platelets are considered as important amplifiers of inflammation. Moreover, the extent and specificity of platelet-leukocyte interactions are determined by the spectrum of receptors on the blood cell surface triggering a variety of intracellular signaling pathways. The facts that the use of known pharmacological agents can result in inhibition of stimulated platelets, blocking the binding of activated platelets with leukocytes are provided. Accumulated knowledge creates the preconditions for simultaneous control of inflammatory and thrombotic processes in various diseases of cardiovascular system.