BACKGROUND: Percutaneous computed tomography (CT)-guided needle biopsy remains one of the most important diagnostic tools in the management of lung nodules; however, it carries a risk of intrapleural dissemination of cancer cells. METHODS: CT-guided lung biopsy was performed before surgery in 171 (34.8%) of 491 patients. A coaxial biopsy system was used that comprised a 19-gauge introducer needle and a 20-gauge core biopsy needle. A total of 412 (83.9%) of the 491 patients underwent intraoperative pleural lavage cytology just after thoracotomy. Intraoperative pleural lavage cytology was performed immediately after opening the thorax, after the pleural cavity was gently washed with 50 mL of saline. RESULTS: No patients had implantation of cancer cells in the chest wall after a median follow-up of 20.2 months. Intraoperative pleural lavage cytology results were positive for 5 (2.9%) of the 171 patients who underwent CT-guided biopsy before surgery, in contrast to 13 (5.4%) of the 241 patients who did not undergo biopsy before surgery. The difference between the biopsy and nonbiopsy groups was not statistically significant. When the analysis was limited to patients with stage IA disease, intraoperative pleural lavage cytology results were positive for 1 (0.8%) of the 128 patients who underwent CT-guided biopsy, in contrast to 3 (2.7%) of the 110 patients who did not undergo biopsy. This difference was also not statistically significant. CONCLUSIONS: No significant association was observed between percutaneous CT-guided lung biopsy and intraoperative pleural lavage cytology results, even in patients with stage IA disease. Percutaneous CT-guided lung biopsy with a coaxial needle does not seem to cause pleural dissemination.