We report two patients with mediastinal abscess developing after surgery for oesophageal cancer who were treated by percutaneous drainage using a unified CT and angiography system, which allows both CT and fluoroscopy to be conducted with the patient on the same bed. Fine needle puncture is performed under CT guidance and this needle is used as a tandem for insertion of the drainage needle under fluoroscopic guidance, making safe puncture possible whilst confirming the position of the needle tip. Moreover, contrast medium can be injected from the drainage tube, allowing the extent of the abscess cavity to be determined by fluoroscopy and CT, thereby making accurate drainage possible.