Diuretic use and overactive bladder syndrome are common in older adults. However, the relationship between the two has not been well studied. Data were collected by self-administered questionnaires including the Urge Urinary Distress Inventory (Urge-UDI) and the Urge Incontinence Impact Questionnaire (Urge-IIQ), and by outpatient chart abstraction. Patients (n=172) had a mean age of 79+/-7.5 (+/-S.D.), 76% were women, and 48% were African Americans; 76% had hypertension, 32% had heart failure, and 66% were receiving diuretics (57% loop diuretics). Overall, 72%, 68%, and 73% of patients, respectively, reported urinary frequency, urgency and urge incontinence. Diuretic use was associated with increased frequency (81% versus 55% non-diuretic; odds ratio (OR)=3.48; 95% confidence interval (CI)=1.73-7.03) and urgency (74% versus 57% non-diuretic; OR=2.17; 95% CI=1.11-4.24) but not with incontinence (OR=1.74; 95% CI=0.87-3.50). When adjusted for propensity scores, diuretic use had independent associations with frequency (adjusted OR=3.09; 95% CI=1.20-7.97) and urgency (adjusted OR=2.50; 95% CI=1.00-6.27). In addition to frequency and urgency, loop diuretic use was also associated with incontinence (OR=2.54; 95% CI=1.09-5.91), which lost significance after propensity adjustment (adjusted OR=1.88; 95% CI=0.57-6.17). Overall summary mean Urge-IIQ score was 1.83+/-0.85 with 1.75+/-0.86, 1.68+/-0.76, and 2.03+/-0.88, respectively, for no diuretic, non-loop, and loop-diuretic patients (one-way analysis of variance (ANOVA) p=0.063). Overactive bladder symptoms were common among ambulatory older adults and were associated with diuretic use, and had stronger associations with loop diuretic use.