We measured the coagulation and fibrinolytic parameters in patients with various angiopathies to clarify the usefulness of the parameters for the evaluation of vascular involvement. The study included 65 patients with cerebral thrombosis at the chronic stage, 47 diabetics with neuropathy associated with diabetic microangiopathy, 15 diabetics without neuropathy, and 16 patients with vasculitic neuropathy associated with collagen diseases. Control subjects were 45 patients with other neurological disorders without symptomatic angiopathies. In cerebral thrombosis at the chronic stage, the coagulation factor VIII (FVIII), von Willebrand factor (vWF), and platelet factor IV were elevated significantly as compared with age-matched controls. Diabetics with neuropathy showed significantly elevated FVIII and vWF in comparison with diabetics without neuropathy and controls. No significant difference in parameters concerning glucose metabolism was observed between the two groups of diabetics. These findings suggest that elevated activities of the coagulation parameters reflect not merely the abnormalities in glucose metabolism but also the presence of microangiopathy which causes diabetic neuropathy. The patients with vasculitic neuropathy exhibited significantly elevated FVIII, vWF and fibrin/fibrinogen degradation products (FDP). The present study demonstrated that FVIII and vWF are useful parameters for the evaluation of the extent of vascular involvement in angiopathies of different etiologies. It is important for the treatment of patients with the angiopathies, to monitor the coagulation parameters which reflect vascular involvement in addition to parameters for the disease activity.