Consumption coagulopathy (CIVD) is a frequent complication of peritoneojugular bypass operation. Preventive treatment applied involves low-dose heparin (1.5 mg/kg/d) to maintain an antithrombin III concentration of at least 65%. Results are evaluated in 6 patients treated by 7 bypass operations. A biologic CIVD developed in 2 cases (29%) but no clinical coagulopathy was observed. This incidence is less than that usually reported, a literature review indicating a biologic coagulopathy in 65% of cases, with clinical evidence in 12.5%. Furthermore, patients with spontaneously elevated AT III levels did not develop CIVD while, in contrast, sufficiently high concentrations of AT III could not be maintained in the 2 patients with coagulopathy. These findings suggest the interest of prevention of a CIVD by the use of this procedure.