Percutaneous transthoracic needle biopsy and transthoracic radiofrequency ablation are interventional procedures, which represent an important alternative to more invasive surgical approaches in the diagnosis and treatment of pulmonary lesions. One of the most common imaging modalities for guidance of both transthoracic procedures is computed tomography. The selection of the appropriate needle as well as intervention planning primarily depends on the characteristics of the lesion and its location. Transthoracic radiofrequency ablation, unlike diagnostic percutaneous transthoracic needle biopsy, represents a relatively novel intervention for the treatment of lung tumors and solitary lung metastases. Pneumothorax and haemoptysis represent two of the most common and expected complications of computer tomography guided transthoracic interventions.