Introduction and Hypothesis <p>Pelvic floor dysfunction (PFD) is common after childbirth, but the role of perineal body dimensions in compartment-specific prolapse remains unclear. To investigate the association between perineal body length and various types of pelvic floor dysfunction in postpartum women, with emphasis on compartment-specific effects.</p> Methods <p>This cross-sectional study included 182 women assessed 30–90 days postpartum at a specialized pelvic floor clinic. Trained examiners measured perineal body length; outcomes assessed were anterior/posterior wall prolapse, uterine prolapse, stress urinary incontinence (SUI), and pelvic floor muscle weakness. Multivariable logistic regression (adjusted for age, pre-pregnancy BMI, delivery mode, postpartum days) was performed. Examiners were partially blinded.</p> Results <p>Perineal body length showed compartment-specific prolapse associations: longer length was inversely associated with posterior wall prolapse (OR 0.544, 95% CI 0.313–0.943, <i>P</i> = 0.030) but positively associated with anterior wall prolapse (OR 3.558, 95% CI 1.133–11.167, <i>P</i> = 0.030; exploratory due to a few non-cases and wide CIs). No significant associations were observed with SUI, muscle weakness, or uterine prolapse. Sensitivity analysis including 16 additional women assessed after 90 days (total <i>n</i> = 198) showed consistent results.</p> Conclusions <p>Perineal body length is differentially associated with anterior and posterior prolapse, reflecting compartment-specific pelvic floor support. The cross-sectional design and lack of pre-delivery measurements mean findings are associative (not causal) and should be validated in larger prospective studies.</p>