Objective To evaluate the effect of single‑dose thoracic paravertebral nerve block combined with patient‑controlled intravenous analgesia on acute and chronic pain in patients undergoing thoracotomy. Methods According to the random number table method, 80 patients undergoing thoracotomy were divided into two groups (n=40): a patient‑controlled intravenous analgesia group (group I) and a single‑dose thoracic paravertebral nerve block combined with patient‑controlled intravenous analgesia group (group P). In group I, patients were not given thoracic paravertebral nerve block, and patients were given a patient‑controlled intravenous analgesia pump at the end of operation. In group P, thoracic paravertebral nerve block was performed on the proposed thoracic level of skin incision under the guidance of ultrasound before operation, 0.3% ropivacaine plus 10 mg dexamethasone 20 ml was administered. Patient‑controlled intravenous analgesia pump was also used at the end of operation in group P. The Numerical Rating Scale (NRS) scores at rest and coughing 6, 24, 48, 72 h after operation were recorded. The incidence and intensity of chronic pain at rest were evaluated 1, 3, 6, 12 months after operation. Results Patients in group P had significantly lower NRS scores at rest and coughing than those in group I 6, 24, 48, 72 h after operation (P<0.05). Group P showed significantly lower NRS scores at rest than group I 1 and 3 months after operation (P<0.05). There was no statistical difference in NRS scores at rest between group P and group I 6 and 12 months after operation (P>0.05). There was no statistical difference in the incidence of chronic pain at rest between group P and group I 1, 3, 6, 12 months after operation (P>0.05). Conclusions Compared with patient‑controlled intravenous analgesia, single‑dose thoracic paravertebral nerve block combined with patient‑controlled intravenous analgesia cannot significantly reduce the incidence of chronic pain at rest 1, 3, 6, 12 months after operation, but can improve acute pain 6, 24, 48 , 72 h after operation and chronic pain 1 and 3 months after operation in patients undergoing thoracotomy.