Since its introduction in 1999 by Friedrich, the titanium vocal fold medialization implant (TVFMI) is widely used for medialization thyroplasty in glottal closure insufficiency. The purpose of this study was to investigate the long-term functional outcome after medialization thyroplasty using TVFMI. Between 1999 and 2009 123 patients (mean age 55.3 years, 76 male and 47 female) underwent medialization thyroplasty with the TVFMI (96 left, 27 right). For purpose of long-term follow-up, 33 patients could be examined. Prior to surgery, about 8 weeks and at least 1 year after surgery perceptual, acoustic, aerodynamic and videolaryngostroboscopic examinations have been performed. The interval between surgery and long-term follow-up was on average 57 (23-120) months. None of the 123 patients presented early major postoperative complications (e.g. implant dislocation, dyspnoea with need of tracheostomy, wound infection, postoperative bleeding). In three patients the TVFMI had to be removed 2-6 months after surgery due to granulation tissue formation. In one patient a subepithelial localization of the implant could be seen without necessity of removal. Perceptual and acoustic parameters were significantly improved after surgery with long-lasting effect even years after surgery. Airway resistance (R(aw)) showed an increase over time without a relevant negative impact on the peak expiratory flow (PEF). Medialization thyroplasty using TVFMI allows precise and save positioning of the implant with stable perceptual and acoustic improvement. The only postoperative complication was the development of endolaryngeal granulation tissue resulting in removal of the implant.