Twenty-eight children with HSP and 79 healthy children were entered into study. Activities of protein C, free-protein S and antithrombin, activated protein C resistance, levels of fibrinogen. D-dimer, thrombin-antithrombin complex (TAT), prothrombin fragments 1 + 2 (PF(1+2)), and von Willebrand factor antigen (vWAg) and its activity (RiCof) were investigated in acute and recovery phases of HSP and controls. Fibrinogen, D-dimer, TAT, PF(1+2), vWAg, and RiCof levels in patients with HSP during the acute phase were significantly higher than those of recovery phase and of the controls. A significant correlation was detected between severity of disease and TAT, PF(1+2), vWAg, and D-dimer levels.