PURPOSE: To evaluate the use of CT in patients with vocal cord paralysis due to extralaryngeal cause s ,andto use CT for the assessment of extralaryngeal diseases causing vocal cord paralysis. MATERIALS AND METHODS: Weprospectively studied the results of CT in 41 patients with vocal cord paralysis in whom laryngoscopy revealed nolaryngeal cause and physical examination demonstrated no definite extralaryngeal cause. The extralaryngeal causeof vocal cord palsy was determined after comprehensive clinical diagnosis. Enhanced CT scans were acquired fromthe skull base and continued to the level of the aorticopulmonary window. We used CT to assess the detection ratefor extralaryngeal causes and to extimate the extent of extralaryngeal disease and the distribution of lesions. RESULTS: CT revealed that in 20 of 41 patients(49%) the extralarygeal causes of vocal paralysis were as follows :thyroid cancer(n=10), nodal disease(n=6), esophageal cancer(n=2), neurogenic tumor(n=1), aortic aneurysm(n=1).Lesions were located on the left side in 13 patients(65%), and in the tracheoesophageal groove in 15(75%). CONCLUSION: In patients with vocal cord paralysis in whom no definite lesion is seen on physical examination, CT could be a useful primary imaging method for the assessment of extralaryngeal causes.