Cervical cord compression due to local extension of differentiated thyroid carcinoma (DTC) is an extremely rare condition and, to our knowledge, only one case has been reported in the literature. Among 256 patients with DTC treated at our hospital, we have observed 3 cases of spinal injury due to local extension of DTC. A Brown-Séquard syndrome was detected at physical examination in 2 cases. In both patients, cervical cord compression precipitated a fatal event. In the remaining patient, a radiculopathy C5-C7 was observed. Magnetic resonance imaging was very successful in outlining the mass, clearly differentiating the extrinsic invasion from a metastasis, and allowing the surgical possibilities to be evaluated. Poor cervical uptake of 131I was observed on scans performed in two cases, suggesting a certain degree of cell dedifferentiation. We suggest that cervical spinal injury due to local extension of DTC may be an underreported complication of DTC that seems to condition the patient's outcome. Careful neurological examination is warranted in patients with DTC at stages III-IV and magnetic resonance imaging must be performed when spinal injury is suspected.