This discussion has provided a review of the available literature regarding alterations of hemostasis associated with CPB surgery, the use of prosthetic devices, and apheresis. The key to prevention of CPB hemorrhage is to obtain an adequate preoperative workup. Of extreme importance is an adequate history with respect to bleeding tendencies and thrombotic tendencies in both the patient and the family; of equal importance is a careful history regarding the use of drugs affecting hemostasis, especially drugs known to interfere with platelet function. A careful physical examination, searching for clues of a real or potential bleeding diathesis, may also prevent catastrophic cases of hemorrhage. An adequate presurgical screen must be performed in surgical patients. In addition to the usual prothrombin time, partial thromboplastin time, and platelet count, a standardized template bleeding time (and thrombin time in patients subjected to CPB) should be performed. The use of these simple testing modalities will guard against significant defects in vascular and platelet function. Most instances of nontechnical surgical and cardiovascular surgical hemorrhage are due to several well-defined defects in hemostasis that should be readily controlled if approached in a logical manner as a team effort among surgeons, pathologists, and hematologists.