Objective: To determine the impact of modifiable surgical factors on ossiculoplasty outcomes after controlling for ear environment risk. Study Design: Multi-institutional retrospective review. Setting: Six tertiary care centers from 2011 to 2019. Patients Adults and children. Interventions: Ossiculoplasty, including synthetic ossicular replacement prosthesis, autograft interposition, bone cement repair, and mobilization. Main Outcome Measure: Correlation between modifiable surgical factors and pure-tone average air-bone gap (ABG) at most recent audiogram after controlling for preoperative risk using the statistically validated Ear Environment Risk (EER) score. Results: A total of 1,679 cases were included with a median follow-up time of 20 months (IQR, 5–51). After controlling for EER score, malleus engagement of prosthesis yielded favorable ABG versus direct contact to tympanic membrane without malleus engagement (beta = −2.4 dB [−3.8, −1.1], p < 0.001). For total ossicular replacement prostheses (TORP), use of a footplate prosthesis yielded favorable ABG as compared with no footplate prosthesis (−3.6 dB [−6.1, −1.1], p = 0.005). For synthetic prostheses, polyethylene prostheses had a less favorable ABG compared with full titanium or titanium with hydroxyapatite prostheses ( p < 0.05). In cases where the malleus was not engaged in reconstruction, amputation of the malleus head yielded worse ABG (+3.9 dB [1.2, 6.7], p = 0.005). There was no significant difference ( p > 0.05) in ABG for single-stage versus multistaged approach, use of a cartilage cap over the prosthesis versus no cartilage, use of bone cement to secure a PORP to the stapes versus no cement, mastoid cavity obliteration versus no obliteration, and incudostapedial joint reconstruction with joint prosthesis/bone cement versus synthetic PORP. Conclusions: With statistical correction for ear environment risk, several modifiable surgical factors are noted to impact ossiculoplasty hearing outcomes. Level of Evidence: 4.