Introduction: The diagnosis of peripheral pulmonary lesions (PPL) poses a significant challenge, prompting the widespread utilization of various modalities to ensure the precision in diagnosis. This study aims to assess the diagnostic accuracy of computed tomography-guided percutaneous transthoracic needle biopsy (CT-PTNB) in the context of pulmonary malignancy. Methods and materials: This multicenter retrospective observational study, included 1317 cases of CT-PTNB performed on adult patients with PPLs from January 2018 to December 2022 in Mashhad, Iran. The pathology results of CT-PTNB from 94 cases were compared to the definitive pathology results obtained through methods such as surgery to assess the sensitivity, specificity, and overall accuracy of CT-PTNB in diagnosing of pulmonary malignancy. Results: CT-PTNB exhibits an accuracy of 82.98%, with sensitivity and specificity rates of 75.41 and 91.43%, respectively. This study underscores the issue of false-negative results in CT-PTNB and underscores the importance of integrating clinical, radiological, and additional diagnostic modality to guide diagnostic decisions. Conclusion: In this large-scale multicenter study, the accuracy of CT-PTNB for diagnosis of pulmonary malignancy is acceptable but fairly low compared to previous studies.