Patients with documented pre-eclampsia of pregnancy were utilized on this study. Various clotting factor activities were measured and these included the prothrombin time (PT), partial thromboplastin time (APTT), fibrinogen (FIB), and clotting factors II, V, VII, VIII, X and XII plus the platelets. Statistical analysis of the data indicates that the activity of many clotting factors was significantly changed due to pre-eclampsia, in general, being elevated over normal pregnant controls. This was primarily reflected in the common pathway portion of the clotting cascade.