Disseminated intravascular coagulation (DIC) is a severe life-threatening acute bleeding disorder. Traumatized tissues, tumors, necrotic tissues, or bacterial endotoxines release similar material in the blood to the tissutal factors activating the coagulation cascade. This preliminary study was aimed at verifying the risk of DIC in patients undergoing US-guided transperineal prostatic biopsy with Chiba and Tru-Cut needles. To evaluate the activation degree of coagulation factors in the circulation, the authors measured the concentrations of urinary fibrin degradation products in 10 patients undergoing US-guided transperineal prostatic biopsy, both before and after biopsy, every second hour, for 24 hours. Every tube of urine sample contained soya bean trypsin inhibitor and bovine thrombin to prevent any further fibrin degradation during incubation period for the possible presence of blood in urine samples. The results showed that 7/10 patients had marked increase in urinary fibrin degradation product levels (up to 800 micrograms%), with a 3-phase trend: early peak after 2-6 hours, middle peak after 6-14 hours, and late peak after 18-24 hours, which proved the activation of the coagulation cascade.