Intra-arterial treatment has become a first-line alternative in the therapeutic arsenal against primary and metastatic hepatic tumors. Despite its proven safety and efficacy, intra-arterial treatment with lipiodol, chemotherapy, and particles carries the risk of complications, some of which can be lethal. We present the case of a 32-year-old woman with multifocal hepatocellular carcinoma treated with microsphere embolization. After the second session, the patient died of a pulmonary embolism composed of particles and tumor cells.