Objective To investigate the optimal concentration of ropivacaine for paravertebral nerve block (PVB) in elderly patients before video‑assisted thoracic surgery (VATS). Methods A total of 80 elderly patients who underwent VATS under general anesthesia from January 2019 to December 2019 in the Affiliated Huai'an First Hospital of Nanjing Medical University were enrolled. According to the random number table method, they were divided into four groups (n=20): a 0.25% ropivacaine for PVB combined with general anesthesia group (group A), a 0.33% ropivacaine for PVB combined with general anesthesia group (group B), a 0.50% ropivacaine for PVB combined with general anesthesia group (group C), and a simple general anesthesia group (group D). Their Visual Analog Scale (VAS) scores at resting and coughing 5 min (T1), 2 h (T2), 4 h (T3), and 24 h after extubation (T4), sufentanil and metaraminol doses during operation, recovery and extubation times, as well as the number of rescue analgesia cases in post‑anesthesia care unit (PACU), and the number of emergence agitation cases, postoperative nausea and vomiting were recorded. Results Compared with groups A and D, patients in groups B and C presented remarkable decreases in VAS scores at resting and coughing, the number of analgesia rescue cases in PACU and the number of emergency agitation cases (P<0.05); group C also showed decreased doses of sufentanil and metaraminol and reduced recovery and extubation times (P<0.05). Compared with group B, the doses of sufentanil and metaraminol and the recovery and extubation times were shortened in group C (P<0.05). There was no statistical difference in the incidence of postoperative nausea and vomiting among the four groups (P>0.05). Conclusions Both 0.33% and 0.50% ropivacaine in PVB can relieve postoperative pain in elderly patients after VATS. But 0.50% ropivacaine is more effective in reducing the use of perioperative analgesics, maintaining hemodynamic stability and promoting the rapid recovery and extubation of patients after surgery, which is recommended as the optimal concentration for elderly patients with VATS.