The application of principles of hemorheology on a process of blood coagulation was suggested by H.H. Hartert - inventor of the thromboelastograph which he introduced in 1947. These principles of applying of a mechanical force and detecting the response of coagulating blood enable to determine a functional evidence of the physiological process producing a hemostatic clot. The thromboelastography, as well as other rheological techniques used for this determination, are introduced evaluating the process in terms of the rate of coagulation, clot elasticity, deformability and permeability. Recent applications of the techniques to the diagnosis of disorders of hemostasis and the study of drug effects on coagulation are presented as well.