Abstract Background Systemic analgesia with paracetamol and nonsteroidal anti-inflammatory drugs plus opioids as a rescue medication had reported to be better than that depend mainly on opioids for postoperative pain relief. Thoracic paravertebral block reported to provide a comparable postthoracotomy pain relief to epidural analgesia, with fewer side effects due to its unilateral effect. Thoracic paravertebral catheter can be inserted intraoperatively under direct vision during thoracic surgery (Sabanathan’s technique). This prospective randomized study was designed to evaluate the safety and efficacy of this technique with continuous infusion of lidocaine compared to systemic analgesia for postthoracotomy pain relief. Results Sixty-three patients were randomized to receive a continuous infusion of lidocaine in the paravertebral catheter for 3 postoperative days (thoracic paravertebral group, n = 32) or systemic analgesia (systemic analgesia group, n = 31). All patients underwent standard posterolateral thoracotomy. There were no significant differences between both groups in age, sex, side, type, and duration of operation. Pain scores measured on visual analogue scale and morphine consumption were significantly lower in thoracic paravertebral group in all postoperative days. Spirometric pulmonary functions were not reaching the preoperative values in the third postoperative day in both groups, but restorations of pulmonary functions were superior in paravertebral group. No complications could be attributed to the paravertebral catheter. Side effects, mainly nausea and vomiting followed by urinary retention, were significantly more in systemic analgesia group (P = 0.03). Also, pulmonary complications were more in systemic analgesia group but not reaching statistical significance (P = 0.14). Conclusion Continuous paravertebral block by direct access to the paravertebral space using a catheter inserted by the surgeon is a simple technique, with low risk of complications, provides effective pain relief with fewer ...