We achieved the dosage of platelet factor 4 (PF 4) and beta thromboglobulin (B-TG), two proteins stored in platelet alpha granules and released from the platelets when activated. These proteins were studied by ELISA technics in patients with type 2 diabetes without any complications (n = 32), with thrombotic complication (n = 32) and in a healthy control group (n = 32). The diabetic patients with complications had significantly elevated plasma levels of PF4 and B-TG compared with diabetic patients without complications, whereas levels of these proteins where normal in control group. These high rates of PF4 and B-TG were significantly related to a disturbance of lipidic balance. Our data suggest that platelet hyperactivation may be a reliable element in the pathogenesis of thrombotic complications in type 2 diabetes.