Computer-tomography-guided needle biopsies are useful for diagnosing, staging, and classification of peripheral pulmonary nodules. However, the procedure carries a risk of iatrogenic pneumothorax. This report describes a patient-case where a woman had undergone a computer-tomography guided biopsy. Approximately 4 hours following discharge the patient was admitted to the emergency ward with severe chest pain and dyspnea. Chest x-ray revealed bilateral pneumothorax and subcutaneous emphysema at the biopsy site. Pleural drainage was administered on the patient's right side. Another chest x-ray following drainage showed regression of pneumothorax on both sides thus indicating communicating pleural cavities. Medical history revealed that the patient had been thymectomized 2 years earlier and a computer tomography visualized that the patient lacked mediastinal separation of the two pleural cavities. It is possible that patients with a history of mediastinal or thoracic surgery should be observed longer following procedures carrying risk of iatrogenic pneumothorax.