Diabetes is associated with a hypercoagulable state. Blood hypercoagulability may accelerate atherosclerosis and the diabetic microvascular complications. Thrombin-antithrombin III complex (TAT) and fibrinogen levels are parameters of coagulation and fibrinolysis. In the present study, we examined the risk factors for the diabetic microangiopathy including TAT and fibrinogen levels. To investigate the relationship between the clinical parameters and microangiopathy in type 2 diabetic patients, the clinical parameters of subjects with microangiopathy were compared with those of subjects without microangiopathy. The clinical parameters were as follows: age at examination, duration of diabetes, fasting plasma glucose (FPG) level, HbA(1C) level, insulin level, TAT level, fibrinogen level, lipoprotein (a) (Lp(a)) level, total cholesterol level, triglyceride level, HDL cholesterol level and existence of hypertension. The plasma TAT and fibrinogen levels were significantly higher in patients with retinopathy or nephropathy than in patients without these complications. Moreover, fibrinogen levels of patients with microalbuminuria or background retinopathy were significantly higher than those of patients with normoalbuminuria or no retinopathy. The duration of diabetes was significantly longer in patients with any microangiopathy than in patients without it. Multiple regression analyses showed that duration and fibrinogen level were independent factors associated with the existence of retinopathy or nephropathy. Our data show that the disorder of coagulation and fibrinolysis is significantly associated with diabetic retinopathy and nephropathy and exists at the early stage of microangiopathy.