Upper airway obstruction of patients with obstructive sleep apnea syndrome (OSAS) occurring during sleep can appear at multiple sites. Successful results of hyoid myotomy with suspension (HM) in the treatment of hypopharyngeal obstruction performed under general anesthesia have been reported. However, many OSAS patients have difficulty at the induction of anesthesia and intubation. They are predisposed to specific complications owing to anatomical abnormalities of the airway and the existence of an underlying syndrome. The purpose of this study was to assess the safety and efficacy of HM for the treatment of OSAS under local anesthesia. Thirty-two OSAS patients with hypopharyngeal obstruction underwent HM under local anesthesia. The hyoid bone was suspended to the superior aspect of the thyroid cartilage. Uvulopalatal flap was an adjunct surgical procedure for palatal obstruction. Patients had a mean age of 39.2+/-5.7 years and a body mass index of 29.3+/-2.4 kg/m(2). Data on the patients were compared from preoperative to postoperative assessment points. Statistical analysis was performed using the Student's t-test. All patients tolerated the procedure well. The mean follow-up was 8.1+/-2.4 months (range 5 to 10 months). The mean RDI decreased from 44.5+/-8.7 to 15.2+/-5.6 ( P<0.001), and the lowest oxygen saturation increased from 82.1+/-3.7% to 87.9+/-2.7% ( P<0.01). The Epworth sleepiness scale improved from 14.1+/-2.2 to 8.2+/-2.3 ( P<0.01), and the snoring scale improved from 8.5+/-1.8 to 3.5+/-1.7 ( P<0.001). Postoperative complications included transient dysphagia in 3% of the patients and transient aspiration in 9%. Bleeding, infection and airway obstruction were not observed. Most patients had mild to moderate pain (visual analog scale <or=7) for 5 to 7 days after the procedures. Responders were defined as OSAS patients who had a reduction in the respiratory disturbance index (RDI) of 50% or more and a RDI of 20 or less after surgery. By these criteria, 78% of the patients were regarded as having responded to HM. A significant reduction in the RDI and clinical improvements were observed after HM. It appears to be a safe, inexpensive and effective procedure that can be performed under local anesthesia with a low probability of complications.