Necrotizing fasciitis is characterized by necrosis with extension over fascial planes and mixed aerobic-anaerobic etiologies. Necrotizing fasciitis is uncommon in children and seldom involves the head and neck area. An infant who developed necrotizing fasciitis involving the parapharyngeal space is described. Chronic dental pathology was probably the initial focus of infection. The patient had a left hemiparesis due to a right middle cerebral artery infarct. Carotid angiography demonstrated complete occlusion of the right internal carotid artery, probably secondary to inflammatory arteritis or direct compression along its course through the parapharyngeal space. Mixed aerobic-anaerobic etiologies predominate in infections of the potential spaces of the head and neck as was demonstrated in this patient. The patient recovered, but had neurologic sequelae. Prompt and aggressive therapy is necessary in patients with necrotizing fasciitis syndromes in order to avoid such severe complications.