Undertreatment of postoperative pain continues to be a major problem internationally. The solution does not seem to be the development of new analgesic drugs or technologies but the development of an appropriate organization that utilizes existing expertise. Evidence suggests that the introduction of an Acute Pain Service (APS) reduces patients' pain intensity, but other outcome benefits are modest. Although the number of hospitals with an APS is increasing, the literature is unclear about the optimal structure, staffing, and function. There is a need for the development of well-defined APS criteria with which to assess performance and compare with national standards.