Purpose of the study: There is continuing uncertainty about the selection of acute pain management techniques. This study aims to analyse the effectiveness and safety of acute pain management from a large prospective database. Methods: From January 1991 to December 2005 patients managed by the Acute Pain Service at Westmead Hospital where formally assessed during a daily ward round and data was recorded on a form. This information was entered into a computerised database and was analysed using statistical software. Information collected included demographics, anatomical site of surgery, surgical speciality, analgesic technique, pain score, and adverse events (predefined list). Results: Patient details: total number 27,752, ages ranged from 1 to 103 years (median 46.3), male 38%, female 64%. Site of surgery: lower abdominal 32%, upper and lower abdominal 30%, peripheral 11%, thoracic 6%, spine 3.8%, upper abdominal 2.9%, joint replacement 2.5%. Analgesic technique (n): epidural 5958, PCA morphine 12463, PCA fentanyl 2518, morphine infusion 1739, PCEA pethidine 1358, intrathecal morphine 1034, epidural morphine 458, nerve sheath catheter 255. Pain scores on day one were 2 or less for 79% of patients. Variables associated with increased pain score included: young age, site of surgery, and analgesic technique. Adverse events: respiratory rate <8/min 0.78%, naloxone given 0.65%, hypotension due analgesia 0.6%. Factors associated with respiratory depression were: analgesic technique (systemic opioid), type of surgery, increased age, male sex, and high pain scores. Factors associated with PONV (treated) were: young age, female sex, type of analgesia, type of surgery, high pain score. Conclusions: Analgesic effectiveness and adverse events are related to patient factors, nature of surgery and choice of analgesic technique.