Transcatheter arterial embolization (TACE) is a minimally invasive procedure that requires precise visualization of the feeding vessels to liver tumors for proper catheter placement and effective therapy. The use of three-dimensional (3D) rotational angiography (RA) can be extremely useful to the interventional radiologist during TACE while the patient is on the catheterization table. This report demonstrates the role of 3D RA in interventional oncology by presenting two cases of hepatocellular carcinoma with complex vascular anatomy successfully treated because of the information provided by this new technology.