Continuous extrapleural intercostal block (EPIB) with bupivacaine has been reported to be an effective analgesic technique in patients after thoracotomy. We report a retrospective study of EPIB using a continuous infusion of 1% lidocaine hydrochloride at a dose of 1 mg/kg/h. A posterior parietal pleural pocket was created and cannulated with a 16-g polyethylene catheter. Lidocaine was perfused over a 3-day period following surgery. Patients also had access to morphine sulfate via patient-controlled analgesia. Eighteen consecutive posterolateral thoracotomies (in 17 patients) performed during a 6-month period were reviewed. Serum lidocaine exceeded the toxic level of 5 microgram/mL in only one patient, a 104.5-kg man who had a level of 5.9 micrograms/mL on postoperative day 2 but experienced no clinical toxicity. Pain was evaluated by verbal analog scores (0 = no pain and 10 = worst pain), which averaged 3.02, 3.14, and 2.8 in the 3 days following surgery. Mean total daily MS doses were 24.3, 37.75, and 34.32 mg (range, 0 to 94 mg). Sedation was scored on a 1 to 5 scale. Mean scores were 2.78, 2.56, and 2.6. No patient died or had a major respiratory complication. Continuous EPIB with lidocaine appears to be a promising adjuvant technique in the management of postthoracotomy pain. Effectiveness needs to be confirmed in a prospective randomized study.