Awareness during surgery and memory for perioperative events may have substantial psychological consequences for the patient. The risk of awareness during trauma surgery is higher than during most elective procedures due to the fact that administration of adequate concentrations of anaesthetics is not always feasible. As a consequence, the risk of memory formation might be increased. The present review discusses different forms of memory, and the possibilities and limitations of awareness and memory prevention. (C) 2000 Lippincott Williams and Wilkins.