Aims: The Questionnaire for Urinary Incontinence Diagnosis (QUID), a 6-item urinary incontinence (UI) symptom questionnaire, was developed and validated to distinguish stress and urge UI. This study's objective was to evaluate QUID validity and responsiveness when used as a clinical trial outcome measure. Methods: Participants enrolled in a multi-center trial of non-surgical therapy (continence pessary, pelvic floor muscle training or combined) for stress-predominant UI and completed baseline and 3-month diaries, the Urinary Distress Inventory (UDI) and QUID. Data from all treatment groups were pooled. QUID internal consistency (Cronbach's α) and convergent/ discriminant validity (Pearson correlations) were evaluated. Responsiveness to change was assessed with 3-month score outcomes and distribution-based measurements. Results: Four hundred forty-four women (mean age 50) were enrolled with stress (N = 200) and mixed (N = 244) UI; 344 had 3-month data. Baseline QUID Stress and Urge scores (both scaled 0-15, larger values indicating worse UI) were 8.4 ± 3.2 and 4.5 ± 3.3, respectively. Internal consistency of QUID Total, Stress, and Urge scores was 0.75, 0.64 and 0.87, respectively. QUID Stress scores correlated moderately with UDI-Stress scores (r = 0.68, P < 0.0001) and diary stress UI episodes (r = 0.41, P < 0.0001). QUID Urge scores correlated moderately with UDI-Irritative scores (r = 0.68, P < 0.0001) and diary urge UI episodes (r = 0.45, P < 0.0001). Three-month QUID Stress and Urge scores improved (4.1 ± 3.4 and 2.2 ± 2.7, both P < 0.0001). QUID Stress score effect size (1.3) and standardized response mean (1.2) suggested a large change after therapy. Conclusion: The QUID has acceptable psychometric characteristics and may be used as a UI outcome measure in clinical trials. © 2010 Wiley-Liss, Inc.