To develop a "top-five" list of unnecessary medical services in anesthesiology, we undertook a multistep survey of anesthesiologists, most of whom were in academic practice, and a consequent iterative process with the committees of the American Society of Anesthesiologists. We generated a list of 18 low-value perioperative activities from American Society of Anesthesiologists practice parameters and the literature. Starting with this list and proceeding with a 2-step survey using a 5-point Likert scale questionnaire, we eventually identified 5 common activities that are of low quality or benefit and high cost and have poor evidence supporting their use. The 2 preoperative practices in the top-five list addressed the avoidance of unindicated baseline laboratory studies or diagnostic cardiac stress testing. The 3 intraoperative practices involved the avoidance of the routine use of the pulmonary artery for cardiac surgery and the use of packed red blood cells or colloid when not indicated.