The authors implemented medialization thyroplasty with a customized silicone implant in a total of 43 operations (36 patients) in 1999-2003. In 5 of these patients, the medialization thyroplasty was combined with cricothyroid subluxation (3 cases) or adduction of arytenoid cartilage (3 cases). One patient received medialization thyroplasty, cricothyroid subluxation and adduction of arytenoid cartilage. Postoperatively 36 patients reported substantial reduction of their complaints, 5 patients found their voice improved and only 2 patients (5.6%) stated that their voice had not changed. The subjective evaluation was consistent with the findings of laryngoscopy and the preoperative and postoperative phonation parameters (maximum phonation time, maximum sound pressure level, jitter and shimmer). Average maximum phonation time was 6.5 s before surgery and 12.5 s after surgery. Maximum vocal sound pressure level was, on average, about 4 dB higher after surgery. Jitter was reduced from 5.3 to 3.7% and shimmer from 32.3 to 18.6%. The differences between presurgical and postsurgical parameters in our study were all statistically significant, indicating voice improvement. Medialization thyroplasty with a silicone implant was proven to be a successful and safe surgical method for the treatment of vocal fold paralysis.