Purpose <p>This study evaluated the relationship between urethral diverticulum volume (UDv), urethral sphincter complex volume (USCv), clinical and urodynamic characteristics, and surgical outcomes in women with UD.</p> Methods <p>A retrospective study was conducted on 53 female patients who underwent diverticulectomy for UD. They were divided into two groups: proximal/middle UD (pmUD, <i>n</i> = 43) and distal UD (dUD, <i>n</i> = 10). Preoperative assessments included videourodynamic study (VUDS) and magnetic resonance imaging, with a follow-up VUDS 1 month post-surgery.</p> Results <p>Compared to the dUD group, pmUD patients were less likely to present with a vaginal lump (37.2% vs. 80.0%, <i>p</i> = 0.031) but had significantly larger USCv (9.96 ± 5.91 cm³ vs. 5.23 ± 1.19 cm³, <i>p</i> &lt; 0.001) and UDv (6.27 ± 7.40 cm³ vs. 0.84 ± 0.81 cm³, <i>p</i> &lt; 0.001). The pmUD patients had longer surgeries and higher recurrence rates (32.6% vs. 0%, <i>p</i> = 0.018). In the pmUD group, 24 patients had bladder outlet obstruction (BOO) and 25 exhibited high-pressure voiding (&gt; 20cmH₂O). No significant association was found between UDv or USCv and recurrence, unresolved BOO, or high-pressure voiding status. However, a USCv cutoff of ≥ 8.2 cm³ was identified, predicting unresolved high-pressure voiding status post-surgery (<i>p</i> = 0.023). Additionally, 9.3% pmUD patients developed de novo stress urinary incontinence, correlated with larger UDv (11.5 ± 14.3 cm³ vs. 5.9 ± 6.4 cm³, <i>p</i> = 0.02).</p> Conclusion <p>A USCv cutoff of ≥ 8.2 cm³ was identified as a predictor for unresolved high-pressure voiding after diverticulectomy.</p>