OBJECTIVES: To assess the outcome of type II thyroplasty in the treatment of adductor spasmodic dysphonia (ASD). STUDY DESIGN: Prospective case series. METHODS: Thirteen patients with the diagnosis of ASD who were previously treated successfully with botulinum toxin therapy were recruited. Type II thyroplasty as described by Nobuhiko Isshiki was performed on all the patients. A self-rating assessment of the degree of severity and vocal effort were recorded and compared preoperatively and during postoperative follow-up. RESULTS: There were four early failures in our series, with two caused by friable thyroid cartilage. In the early postoperative period, after excluding the early failures, six (66.7%) and seven (77.8%) patients had moderate-good improvement in symptom severity and vocal effort, respectively. During the follow-up period, a further five patients had deterioration of voice quality and were classified as failures. Of these five patients, two patients had reversal of their procedure. At the end of the follow-up period (mean follow-up period of 12 months), six (66.7%) and five (55.5%) patients sustained improvement in symptom severity and vocal effort, respectively. However, only two (22.2%) and three (33.3%) patients had moderate-good improvements in symptom severity and vocal effort, respectively, after 12 months. CONCLUSIONS: Botulinum toxin injection remains the gold-standard treatment for ASD in our center. Potential patients for type II thyroplasty need to be carefully selected and counseled by a multidisciplinary team of otolaryngologists, neurologists, and speech pathologists.