Both aortic dissection and tension pneumothorax are conditions that require urgent treatments. However, the diagnosis of these emergencies is sometimes challenging because of various symptoms and difficulty obtaining their medical history due to severe conditions. Here, we present the case of a patient with type A aortic dissection associated with tension pneumothorax. This is the second report of such a case worldwide. A 61-year-old man presented to the emergency department with sudden-onset chest and back pain. Upon presentation, his blood pressure was 97/58 mmHg, oxygen saturation on room air was 96%, and respiratory rate was 28 breaths/min. His physical examination revealed no jugular venous distention; however, breath sounds over the left lung were diminished. Bedside chest radiography revealed left tension pneumothorax with mediastinal shift to the right. Needle and chest tube thoracostomies were performed; however, the patient's vital signs did not improve and reexpansion pulmonary edema developed following tube thoracostomy. Contrast-enhanced computed tomography revealed type A thrombosed aortic dissection with bullae in the upper lobe of the left lung. Therefore, the patient was admitted to the intensive care unit, conservatively treated, and discharged without any complications. In conclusion, type A aortic dissection may be associated with tension pneumothorax and should be considered if the patient's vital signs do not improve even after decompression of the tension pneumothorax.