The common carotid artery (CCA) usually divides into the internal carotid artery (ICA) and the external carotid artery (ECA). We present an extremely rare case of a non-bifurcating carotid artery through which intra-arterial chemotherapy for laryngeal cancer was administered. The CCA angiogram, as well as ultrasonographic evaluation of the carotid arteries, demonstrated a non-bifurcating CCA that subsequently constituted the ICA. Furthermore, several branches normally given off by the ECA arose directly from the single carotid artery. Superselective intra-arterial infusion of cis-diamminedichloroplatinum (II) (CDDP) was subsequently performed.