Despite major advances in knowledge and development of efficient techniques for pain control, many patients on surgical wards suffer from modest to severe pain following surgery or trauma. Therefore, in the University Hospital of Kiel, Germany, an anaesthesiology-based acute pain service (APS) was started in 1985 to improve this situation. Organization of an APS. The anaesthesiologist in training who manages the recovery unit serves as an APS for surgical wards and is supervised by a consultant. The anaesthesists on call are responsible after regular working hours. The activities of the APS are as follows: 1. Induction of sufficient postoperative analgesia in the recovery unit for all surgical patients. 2. Clinical rounds on all patients receiving epidural analgesia (EA), other forms of regional analgesia, or patient-controlled analgesia (PCA) every morning and throughout the day if necessary. 3. Additional consultations for postoperative pain management for other patients on request. 4. Assessment and documentation of the clinical status of the patient, quality of analgesia, and side effects. 5. Writing orders for further treatment. 6. Continuing consultations and informal education for ward nurses, physiotherapists, and surgical staff; formal medical training for ward nurses in postoperative pain management. Activity of the APS. From 1985 to 1992, 1947 patients on normal wards were treated (EA: 1736, PCA: 183). Epidural analgesia was performed using a standard protocol with bupivacaine 0.175%-0.25% infused continuously with top-ups if needed (mean 240 mg/day, range 75-600 mg; median duration 7 days, range 1-53, Table 1). Demand for further treatment was proved by day-to-day withdrawal. Since the introduction of an APS, complications of EA such as hypotension (1985/1986:5.1%; 1987/1992:0.5%, Table 3) and insufficient analgesia due to dislocation or other technical complications could be reduced significantly (Table 3). Dermal infections were seen in 2.6% of patients, with a significantly higher incidence in patients with arteriosclerotic diseases (4.1%). Epidural opioids were used in only 46 selected cases on surgical wards. Nevertheless, 2 cases of marked respiratory depression occurred. The overall risk of complications during postoperative EA could be reduced from 1:11 cases in the first 2 years to 1:20 in the last 6 years since introducing the APS. For other regional procedures (e.g., interpleural analgesia) no complications were recorded. PCA was performed using a standard protocol with tramadol or piritramide without background infusion (Table 6). The loading dose was titrated in the recovery unit.(ABSTRACT TRUNCATED AT 400 WORDS)