We report the fifth case of neoplastic involvement of the infrahepatic portion of the inferior vena cava, observed in a young woman affected by a left adrenal cortical carcinoma. The intracaval extension of a neoplastic thrombus from an adrenal tumor is a rare complication that should not be considered a dismal prognostic factor and does not contraindicate tumor resection with curative intent. Caval invasion must be preoperatively investigated to plan the correct surgical access and avoid the risk of neoplastic embolization.