Although about 30% of gastric cancers have distant metastasis at the time of initial diagnosis, metastatic tumor embolus in the main blood vessels is not common, especially in the main artery. The report presents, for the first time, an extremely rare clinical case of a metastatic embolus in the common carotid artery (CCA) from primary gastric cancer. Metastatic embolus from the primary tumor should be considered when patients present with gastric cancer accompanied by intravascular emboli. The patient should be actively examined further so as to allow early detection and treatment.