Spontaneous pneumothoraces can occur without obvious underlying lung disease (primary) or in patients with known underlying lung disease (secondary). Management guidelines for spontaneous pneumothorax have been published by major professional organizations, but awareness and application among clinicians seems poor. First episodes of primary spontaneous pneumothorax can be managed with observation if the pneumothorax is small. If the pneumothorax is large or if the patient is symptomatic, manual aspiration via a small catheter or insertion of a small-bore catheter coupled to a Heimlich valve or water-seal device, should be performed. In general, definitive measures to prevent recurrence are recommended after the first recurrence of the pneumothorax, and can be achieved by medical (e.g. talc) or surgical (video-assisted thoracic surgery) pleurodesis. Secondary pneumothoraces should be treated with chest tube drainage followed by pleurodesis after the first episode to minimize any risk of recurrence. Traumatic pneumothoraces may be occult (not seen on an initial CXR) or non-occult. The majority are treated by placement of a chest tube. Selected patients may be treated conservatively, with approximately 10% of these patients eventually requiring chest tube placement. Iatrogenic pneumothoraces have a myriad of causes with transthoracic lung needle biopsy being most common. Transthoracic needle biopsy-related pneumothoraces have CT findings that can predict their occurrence and the need for chest tube placement. Iatrogenic pneumothoraces, regardless of cause, may be managed by observation or small bore chest tube placement, depending upon patient stability and the size of the pneumothorax.