Both regional analgesia and systemic opioid therapy (e.g. PCA) are commonly used for pain relief following thoracic surgery. Many anaesthesiologists are reluctant to use thoracic epidural analgesia on general surgical wards. Therefore, we investigated in a prospective randomised study the efficacy of intercostal blocks (ICB) or interpleural analgesia (IPA) compared to PCA with systemic opioids (PCA). Following ethics committee approval and informed consent, 45 thoracotomy patients were randomised for postoperative pain management: group 1: intravenous PCA with piritramide (PCA-control), group 2: intercostal blocks of the segments concerned with 5 ml bupivacaine 0.5% at the end of surgery and 6 hours thereafter (ICB), group 3: interpleural analgesia with 20 ml bupivacaine 0.25% applied every 4 hours using a catheter placed during surgery near the apex of the pleural space (IPA). Patients in the ICB and IPA groups were able to obtain additional pain relief by PCA with piritramide. Alternative medication for all groups in case of insufficient analgesia was metamizol. Both regional analgesia groups used significantly less piritramide up to the 3rd (IPA) or 7th (ICB) postoperative day than the control group (p < 0.05). The consumption of metamizol was lower as well (n. s.). No significant differences between the study groups were observed with regard to pain scores (visual analogue scale VAS) at rest, during deep inspiration, coughing or mobilisation. Respiratory parameters as forced vital capacity, forced expiratory volume (1 sec) and peak flow (FVC; FEV1; PF) were reduced significantly following thoracotomy and showed a slow restitution in all three study groups without major inter-group differences. Intercostal blocks and interpleural analgesia significantly reduce opioid demand following thoracotomy and are effective means of postoperative pain management. Nevertheless, in contrast to epidural analgesia, both methods have to be supplemented by, or combined with, systemic analgesics in most patients. On the other hand, compared to epidural analgesia, ICB and IPA are less invasive and easier to manage on general surgical wards.