In Gaucher disease type I bleeding is a common presenting symptom, that may manifest itself as frequent nose bleeds, easy bruising but can also cause substantial bleeding after surgical or dental procedures and may occur in association with pregnancy or delivery . The bleeding tendency is usually considered to be secondary to thrombocytopenia However 50,000 platelets are enough in healthy people to give a normal bleeding time but are associated with significant bleeding tendencies in Gaucher patients. Bleeding tendency might be attributed by genetic inherited or Gaucher related coagulation factors abnormalities which in some cases stabilize with ERT. However, In other cases the etiology is an abnormality of platelet function. This thrombocytopathy has not been delineated and apart from a few aggregation studies, no systematic analysis has been published that convincingly shows the cause of the disturbed function. While, experience shows that enzyme replacement (ERT, i.e: imiglucerase, Cerezyme®) reduces this bleeding tendency, in part due to the improvement in the thrombocyte count and elevation in coagulation factors, it is less clear what effect ERT has on the thrombocytopathy. This has clinical significance when patients need to be prepared for surgery or delivery or in the event of a major bleed. There is no consensus as to how patients should be prepared or treated. Different centres use different approaches. When the procedure is elective ERT is appropriate but in other situations DDAVP, fresh frozen plasma and platelet infusion are possible treatments. Even activated factor VII has been used when bleeding was not controlled. As in any other coagulation abnormality, treatment should be tailored to the specific cause of the bleeding diathesis. The aim of this study is to define the etiology of platelet dysfunction in Gaucher patients.