Those of us who study and teach in the expanding world of geriatric surgery have joined geriatricians in loudly proclaiming the human and financial costs of postoperative delirium. However, our proclamations have often fallen on deaf ears because it has been difficult to prove with sound evidence that it is worth devoting resources to this surprisingly common surgical complication. The study by Gou et al1 in this issue documents the initial inpatient hospital costs of an episode of postoperative delirium ($20 327), the yearly cumulative costs ($44 291), and the total costs to our health care system of the 700 000 such annual delirium episodes in the Medicare population ($32.9 billion).