In 20 chronic uremic patients on maintenance hemodialysis, who were not taking any medication known to affect platelet function, the following investigations were carried out: platelet count, fibrin/fibrinogen degradation products, fibrinogen and plasminogen concentration, platelet adhesiveness, clot retraction and platelet aggregation induced by ADP, ristocetin, fibrinogen, collagen and epinephrine. The only significant abnormal result was a decreased clot retraction. We consider many cases of so-called uremic bleeding to be caused by the medication taken and conclude that on well-controlled hemodialysis treatment, bleeding tendency should not be a major problem.