Background and Objectives Malleus fixation is one of the important causes of persistent conductive hearing loss. This study was designed to evaluate the clinical manifestation and the treatment outcome of malleus fixation. Subjects and Method This study was a retrospective review of medical records between 1989 and 2008. Patients diagnosed as malleus fixation by intraoperative findings at the Department of Otorhinolaryngology, Seoul National University Hospital were included. Those cases with chronic otitis media and congenital ossicular anomaly involving the incus or stapes were excluded. A total of 13 patients were included (M : F=4 : 9, Mean age: 24.4 years old). Results All patients (100%) complained of hearing loss. Preoperative mean air-bone conduction gap was 34.4 dB and 5 (83.3%) out of 6 patients had A-type in impedence audiometry and 3 (75%) out of 4 patients had negative results in Gelle test. In the temporal bone computed tomography (TBCT) findings, we could identify bony spicules (2 cases), sclerosis of ligament (3 cases) and epitympanic contraction (2 cases). According to the different causes of conductive hearing loss, corrective surgery was performed: the release of bony ankylosis (2 cases), lysis of ligament (6 cases) and ossiculoplasty (5 cases) were performed. There was a statistically significant improvement in air-bone conduction gap (34.4 dB vs. 20.3 dB, p=0.009) after surgery. Conclusion Considering the improvement of air-bone conduction gap after the corrective surgery, clinical suspicion of malleus fixation is important in cases of unknown conductive hearing loss.