OBJECTIVE: To determine which ear environment risk factors impact ossiculoplasty hearing outcomes and to generate a statistically-valid grading system for ossiculoplasty outcome reporting. STUDY TYPE: Retrospective case series. METHODS: A multi-institutional database was generated from cases performed between 2011 and 2019. Preoperative and postoperative hearing thresholds were recorded alongside potential ear environment risk factors. Multiple variable linear regression statistical analyses of risk factors were applied to determine independent association with postoperative pure tone average air-bone gap (PTA-ABG). Significant factors were used to generate a statistically-weighted grading scale of Ear Environment Risk (EER). RESULTS: 1679 cases had a mean follow-up time of 33.6 months (SD 36.3) and a mean postoperative PTA-ABG of 21.2 (SD 12.8). Multiple revision status (p <
0.001), presence of canal wall down mastoidectomy cavity (p = 0.020), absent malleus (p <
0.001), absent stapes superstructure (p = 0.016), frequent otorrhea (p = 0.008), pediatric age (p <
0.001), and blunted/lateralized tympanic membrane (p = 0.003) were independently correlated with PTA-ABG. These factors were incorporated into an EER Scoring System with four distinct risk groups wherein each risk group was significantly correlated with PTA-ABG, and this grading system was better correlated with PTA-ABG (Kendall's τ = 0.193) than other existing published grading scales. CONCLUSION: Grading environment risk according to a novel EER scoring system generates meaningful risk groupings that correlate with ossiculoplasty postoperative PTA-ABG, and this holds potential to frame reporting of hearing outcomes for future ossiculoplasty research. LEVEL OF EVIDENCE: 3 Laryngoscope, 135:S1-S11, 2025.