The objectives in treatment of bilateral vocal fold immobility (BVFI) are to achieve adequate airway, preservation of voice quality and laryngeal competence. The present prospective study was designed to evaluate precisely the efficiency and long-term clinical outcome in a series of 13 patients with irreversible BVFI, consecutively managed with endoscopic radiosurgical posterior transverse cordotomy (ERPTC). The operation was performed endoscopically using an Ellman Radiosurgical Instrument and a specially designed electrode. Pre- and post-operative inspiratory function measurements and acoustical vocal analysis were conducted on the patients and were tested for potential statistical relation to successful rehabilitation of the airway. One-step, successful restoration of the airway was achieved in all patients. The post-operative improvement of spirometric values was statistically significant (p < 0.0001), and during the follow-up period of (six to 30) months, airway stability was demonstrated in all patients. In terms of acoustic analysis a non-significant difference was found between pre- and post-operative vocal functions (p > 0.05). This management approach offers an alternative to laser procedures, it provides a ’one-stage’ solution for permanent bilateral vocal fold immobility, and avoids terminal loss of voice quality. The authors’ data confirm the safety, ease of performance, and efficiency of ERPTC in patients with bilateral immobile vocal folds.