Because of the increase of ultrasonographic exams, nonparasitic cyst of the liver is frequently encountered. Some giant cysts have complications. The surgical treatment for complicated forms consists in resection of the protruding part. We report a case of a giant non parasitic cyst of the liver which was responsible of a compression of the inferior vena caval with thrombus. The resection of the thrombus was performed after a double control of the vena cava and a control of the aorta. The fenestration of the cyst was performed in a second time.