Objective:To compare the effectiveness of primary malleostapedotomy with revision malleostapedotomy for otosclerosis.Methods:From April 2002 to December 2017, 70 consecutive patients with otosclerosis who underwent malleostapedotomy were reviewed. Depending on the primary malleostapedotomy (P-MS) or revision malleostapedotomy (R-MS), the patients were divided into P-MS group or R-MS group.The intraoperative findings and hearing results before and after surgery were compared between the two groups. ALL data were analyzed using SPSS 23.Results:Totally 73 malleostapedotomy were performed in 73 ears of 70 patients, including 38 P-MS and 35 R-MS. There was no significant difference between the two groups in sex ratio, age and operated ears ( P>0.05 for all). The most common finding at P-MS was incus fixation (50.0%, 19/38) versus prosthesis displacement for R-MS (60.0%, 21/35) . Overall, the air-bone gap (ABG) improvement in P-MS were (18.1±8.2) dB in 0.5-3 kHz and (18.3±8.5) dB in 0.5-4 kHz, without significant difference to those in R-MS ( P>0.05) . 31.4% of R-MS in 0.5-3 kHz and 22.9% R-MS in 0.5-4 kHz achieved an ABG<10 dB, significantly lower than those of P-MS (65.8% in 0.5-3 kHz and 57.9% in 0.5-4kHz; P<0.05). Failure (postoperative ABG>30 dB) occurred in 11.4% in R-MS and 0 in P-MS (for 0.5-3 kHz and 0.5-4 kHz). The incidence of postoperative sensorineural hearing loss (>10 dB increase in bone conduct) in R-MS group was 8.6% in 0.5-3 kHz and 0.5-4 kHz, without significant difference to those in P-MS ( P>0.05) . 80.0% (20/25) of first R-MS achieved ABG<20 dB, compared to 37.5% (3/8) of second R-MS with ABG<20 dB. Conclusions:Although both P-MS and R-MS can significantly improve hearing, with similar risk of inner ear damage, R-MS is less effective and poses a higher risk of failure than P-MS. For patients with insufficient hearing improvement after first R-MS, conventional hearing aids or implantable hearing devices may be considered as an alternative.