Diagnostic and surgical features of lateral cervical chemodectomas are discussed in relation to a personal series of 13 patients with carotid body tumors and 7 with tumors of the intravagal glomus. Clinically, these affections are poor in symptomatology, those of the carotid glomus presenting as an isolated cervical tumor, intravagal glomus tumors as parapharyngeal masses of the retrostyloid type. Arteriographic findings are discussed in detail, as they constitute the only pathognomonic signs, enable differentiation between the two tumor sites, and supply essential pre-operative data: location of the pedicles, possible invasion of arterial walls, and the limits of the tumor. Surgical approach should be wide to enable control of the distal end of the internal carotid artery, if necessary under the base of the cranium, excision of the tumor usually being possible by employing the subadventitial resection technique.