Platelet function and plasmatic coagulation of 51 patients with Duchenne muscular dystrophy (DMD) were studied in order to find an explanation for the known substantial blood loss in spinal surgery of these very patients. A normal plasmatic coagulation and a slight but not significant increase of bleeding time was found. However, a significant deficiency of platelet adhesion and ristocetin induced aggregation (P < 0.001) as well as a marked reduction of expression of glycoprotein i.v. (synonyms: GPIV, GPIIIb, CD36) to 50% were detected. We conclude from our study, that this finding of deficiency of platelet function in DMD patients is of no importance in everyday life and minor operations, e.g. lower limb surgery. In major spinal surgery, however, the platelet function deficiency occurs. A decompensation of platelet adhesion as well as aggregation capacity can be assumed due to the unavoidable intraoperative dilution effect by the inevitable volume replacement.