Aims: This study aims to discuss the relationship between complications and patient characteristics and lesion properties in the transthoracic fine needle aspiration biopsy (TTFNAB) procedures performed for lung lesions and the treatment applied in our clinic to eliminate these complications. Methods: In this retrospective study conducted from July 2014 to August 2017, the CT-guided TTFNAB was performed on 186 patients (145 males, 41 females) who were considered to have malignancies on their clinical evaluation, CT, and PET CT results. Results: After 186 CT-guided TTFNAB interventions, a total of 24 (12.9%) patients developed procedure-related pneumothorax. Of these patients, 7 had a limited and minimal pneumothorax and no treatment was required for them, while 17 had a large and increasing pneumothorax and manual air aspiration was performed with coaxial needle during the procedure. The number pleural transitions (OR 6.513; 95%, 2,529-16,771 P < 0.001), emphysematous lungs (OR 4.612; 95%, 1,852-11.487 P < 0.001), and the presence of a lesion unrelated to the pleura (OR 8.205; 95%, 3,162-21,291 P < 0.001) can form the basis for the development of a pneumothorax. Conclusion: The chances of developing pneumothorax after TTFNAB depend on number of pleural transition, emphysematous lungs, and non-pleural lesions. However, it is considered that procedures such as manual air aspiration and autologous blood patch may reduce the need for chest tube following the development of pneumothorax.