Spasmodic dysphonia is an uncommon and poorly understood disorder of motor control of laryngeal speech. We analysed 88 patients with spasmodic dysphonia, using chart review. These patients had historical information evaluated for age of onset(mean 39.2 years), duration of symptoms(mean 8.8 years), sex(4.2 : 1 female to male) family history(positive in 16.7%), and primary(84.8%) and secondary(15.2%) etiology : neurological evaluation for other dystonic involvement(40.7%). Eighty-three patients(94.3%) had adductor type of spasmodic dysphonia and 4 patients were abductor type and 1 patient was mixed type. All patients had normal thyroid and parathyroid functions and among 46cases, 8 patients had abnormal brain MRI finding. seventeen patients were evaluated by auditory brainstem response parameters. four out of the 17 patiemts had prolonged wave Ⅰ-Ⅴ interpeak latency.