Radiofrequency thermoablation (RFA) is used to treat unresectable liver tumours. RFA is performed using an abdominal access (laparotomic, laparoscopic and percutaneous). A transpleurodiaphragmatic approach has recently been proposed, particularly for the treatment of tumours which are placed near to inferior vein cava and hepatic veins and which are difficult to reach for an abdominal access. A patient with a liver metastasis of the segment VIII underwent RFA with an associated wedge resection of the segment VII, both were performed with a transthoracic access. Peri- and postoperative complications did not occurred. The patient was discharged on fifth postoperative day, and she is disease free after a follow up of 6 months. A transpleurodiaphragmatic access can be considered a safe and efficacy procedure to perform an RFA of a liver tumour in selected cases.