Pneumothoraces and malignant pleural effusions are commonly encountered clinical problems in a general thoracic surgical practice. Pneumothoraces may be either iatrogenic or non-iatrogenic. Iatrogenic pneumothoraces can occur following transbronchial or percutaneous transthoracic lung biopsy, percutaneous central venous catheter insertion, or thoracentesis. Non-iatrogenic pneumothoraces are encountered frequently in the patient with chronic obstructive pulmonary disease and spontaneous rupture of pulmonary bullae, as well as blunt or penetrating thoracic trauma. Alternatively, pneumothoraces may be idiopathic or "simple pneumothoraces."