Purpose We evaluated the efficacy of nimodipine, a dihydropyridine calcium channel blocker that relaxes vascular and nonvascular smooth muscle, for geriatric urge incontinence. Materials and Methods A randomized, double-blind, placebo controlled crossover trial of 30 mg. nimodipine twice daily for 3 weeks in older persons with detrusor instability and chronic urge incontinence was done. A total of 86 participants with a mean age of 73.4 years were randomized. The primary outcome was the number of incontinent episodes, as measured by the self completion of a 5-day voiding record. Secondary outcomes included the impact of urinary incontinence on quality of life measured with a modified incontinence impact questionnaire (mIIQ) and symptoms, as measured by the American Urological Association (AUA) symptom score. Results A total of 76 (88.4%) participants completed the study. There was no significant difference in the number of incontinent episodes with nimodipine versus placebo, which included a difference of 0.03 incontinent episodes during a 5-day period (p =0.98, 95% confidence interval −2.7 to 2.8). Scores on the mIIQ and the AUA symptom score were not significantly different with nimodipine versus placebo (p = 0.07 and 0.22, respectively). Regardless of initial treatment, participants had improvement with time, that is a period effect, of incontinent episodes (p <0.0001), mIIQ scores (p = 0.0002) and AUA symptom score values (p <0.0001). Conclusions Treatment of geriatric urge incontinence with 30 mg. nimodipine twice daily did not result in a significant improvement of incontinent episodes, mIIQ scores or AUA symptom scores.