Background/aim: This study aims to investigate the effects of thoracic epidural analgesia, before and after surgical incision and in the postoperative period, on thoracotomy pain and stress response. Materials and methods: A total of 45 patients who were scheduled for posterolateral thoracotomy were included in this study. A combination of epidural levobupivacaine and morphine was administered as a bolus before incision (Group 1; n=15), after incision (Group 2; n=15), or at the end of surgery (Group 3; n=15). Additionally, infusion was used in Group 1 and Group 2 during operation. Postoperative patient-controlled epidural analgesia infusion pumps were connected to all patients. Visual analog scale (VAS) scores and morphine consumption were recorded during the postoperative 48 h. Glucose, insulin, cortisol, and C-reactive protein (CRP) levels were compared before surgery and at 4, 24, and 48 h after the operation. Results: There were no differences in the morphine consumption and VAS scores for all measurements among the groups (P > 0.05). Both blood glucose levels at 4 h and CRP values at 48 h were higher in Group 2 than Group 1 (P < 0.05). Cortisol levels at 4, 24, and 48 h after the operation were similar to baseline values in all groups (P > 0.05). Conclusion: The application of thoracic epidural analgesia before and after surgical incision and in the postoperative period did not result in a significant difference in the severity of the postthoracotomy pain and stress response in all groups. Based on our results, we suggest that epidural levobupivacaine combined with morphine provides an effective and safe analgesia and can partially suppress surgical stress response.