Introduction: Percutaneous transthoracic needle biopsy (PCNB) under C-Arm Cone Beam CT (CBCT)-guidance is a safe method of diagnosing lung lesions. In Korea, this usually is performed by interventional radiologists. Various reports show sensitivity for malignancy ranging from 74-95% but specificity is always almost 100%. There are currently no studies describing safety and outcomes of CBCT-guided PCNB performed by pulmonologists. There is potential utility for PCNB to be performed by pulmonologists in areas without interventional radiology support. The objective of the study is to determine diagnostic yield and complications of CBCT-guided PCNB performed by pulmonologists in our institution. Methods: We conducted a retrospective chart review of patients who underwent CBCT-guided PCNB at Chuncheon Sacred Heart Hospital from 2011-2012. We collected clinical and imaging data. A pulmonologist performed procedures using co-axial technique with a G16 biopsy needle. A cytopathologist was present to determine adequacy of sample. Comparison of proportions was used for analysis. Results: Sixty one patients underwent CBCT guided PCNB (34 male, 27 female, mean age 71.8 years). Diagnosis was made in 93.4% comprised of malignant (40, 65.6%) and benign (17, 27.8%), with the remaining 6.6% being non-diagnostic. The overall malignancy sensitivity, malignancy specificity and diagnostic accuracy were 95%, 100% and 96.7%. Complications were he-moptysis (1, 1.6%), and pneumothorax (3, 4.9%). Conclusion: Results show that CBCT-guided PCNB performed by pulmonologists has a high diagnostic accuracy and low com-plication rate.