Amyloidosis associated bleeding diatheses in the surgical patient. The coagulopathies associated with amyloidosis have not been widely appreciated. We encountered a patient with amyloidosis and mildly abnormal coagulation studies who presented for an emergency laparotomy for acute bowel obstruction. Upon gentle manipulation of the bowel, an unexpected bleeding diathesis was manifested by the formation of several large haematomas resulting in a large amount of blood loss (approximately 800 ml). Numerous defects of platelet function and coagulation have been associated with amyloidosis, including abnormal platelet aggregation, increased vascular fragility, factor IX and X deficiencies, decreased levels of alpha-2-plasmin inhibitor, and increased levels of plasminogen. Intraoperative therapy for our patient included the rapid administration of four units of fresh frozen plasma and ten units of platelet concentrate. A review of the pathology and therapeutic modalities for this potentially life-threatening complication is presented. 