A retrospective case-control study was designed to assess risks for elevated post void residual (PVR) in women with pelvic floor disorders. The 1,399 women underwent evaluation including standardized questionnaire, examination, and catheterized PVR. Elevated PVR was defined as >= 100 ml and anterior and apical prolapse was defined as at or beyond the hymen. Overall, the prevalence of elevated PVR was 11%. After matching, the absence of stress incontinence symptoms (OR 0.55, CI 0.33-0.92), the symptoms of vaginal bulge (OR 2.19, CI 1.38-3.48), pelvic pressure (OR 1.79, CI 1.14-2.86), urinary splinting (OR 2.89, CI 1.24-6.74), and presence of prolapse (OR 2.60 CI 1.62-4.18) were significantly associated with an elevated PVR. Only prolapse (OR 1.96 CI 1.37-2.79) maintained a significant association after multivariate analysis. Symptoms alone do not predict which women may have an elevated PVR, but the finding of prolapse at or beyond the hymen is associated with incomplete emptying. Elevated post void residuals cannot be predicted based on symptoms alone; however, prolapse beyond the hymen may help identify women with incomplete bladder emptying.