Transthoracic needle biopsy (TTNB) is done with imaging guidance and most frequently by a radiologist, for the aim is to diagnose a defined mass. It is integral in the diagnosis and treatment of many thoracic diseases, and is an important alternative to more invasive surgical procedures. FNAC is a method of aspiration cytopathology, which with transthoracic biopsy ("core biopsy") is a group of percutaneous minimally invasive diagnostic procedures for exploration of lung lesions. Needle choice depends mostly upon lesion characteristics and location. A recent innovation in biopsy needles has been the introduction of automatic core biopsy needle devices that yield large specimens and improve the diagnostic accuracy of needle biopsy. Both computed tomography and ultrasound may be used as imaging guidance for TTNB, with CT being more commonly utilized. Common complications of TTNB include pneumothorax and hemoptysis. The incidence of pneumothorax in patients undergoing TTNB has been reported to be from 9-54%, according to reports published in the past ten years, with an average of around 20%. Which factors statistically correlate with the frequency of pneumothorax remain controversial, but most reports have suggested that lesion size, depth and the presence of emphysema are the main factors influencing the incidence of pneumothorax after CT-guided needle biopsy. On the contrary, gender, age, and the number of pleural passes have not been shown to correlate with the incidence of pneumothorax. The problem most responsible for complicating outpatient management, after needle biopsy was performed, is not the presence of the pneumothorax per se, but an increase in the size of the pneumothorax that requires chest tube placement and patient hospitalization. Although it is a widely accepted procedure with relatively few complications, precise planning and detailed knowledge of various aspects of the biopsy procedure is mandatory to avert complications.