We report a unique case of chronic contained thoraco-abdominal aneurysm rupture presenting as a Grynfeltt lumbar hernia. A 79-year-old man presented with backpain and a bluish swelling in the left lumbar region in the presence of a non tender aortic aneurysm. CT scan confirmed contained rupture of a type IV thoraco-abdominal aortic aneurysm. The peri-aortic haematoma protruded through the lumbar wall causing a Grynfeltt lumbar hernia. The aneurysm was replaced through a thoraco-phreno-lumbotomy. The patient survived and is doing well six months post-operatively.