Legg-Calve-Perthes disease (LCP) has been reported to be associated with hypofibrinolysis and a deficiency in coagulation. The goal of this prospective study was to confirm or refute these findings and to establish a guide for a screening test. The coagulation systems of twenty-three patients with Legg-Calve-Perthes disease were evaluated by means of the tests which included prothrombin time, activated partial thromboplastin time, antithrombin-III (AT-III), protein C, protein S, lipoprotein(a), and anticardiolipin antibody (ACA). Study subjects were 21 males and 2 females. Mean age was 8.7 years. No abnormal results were found for Antithrombin-III and Protein S, but 2 patients had low Protein C level. Two of 23 patients had Lipoprotein(a) values greater than 30 mg/dl. Another two patients had positive finding for Anticardiolipin antibody. There were no statistical differences in all parameters between Catterall group stage in the patients with Legg-Calve-Perthes disease. We were unable to establish an association between thrombotic tendency and Legg-Calve-Perthes disease based on this prospective study. So, routine screening of patients with Legg-Calve-Perthes disease for abnormalities of antithrombotic factors would be not warranted.