OBJECTIVE To determine if oxybutynin, a bladder relaxant medication, adds to the effectiveness of prompted voiding (PV) in the management of urinary incontinence among nursing home residents. METHODS Randomized, placebo-controlled, double-blinded, dose-adjusted, crossover trial of oxybutynin added along with PV. METHODS Seven nursing homes in Los Angeles County, California. METHODS Seventy-five nursing home residents with predominantly urge incontinence, whose incontinence did not respond well to a trial of PV. METHODS The frequency of incontinence, measured as the percentage of hourly (7 AM to 7 PM) physical checks over a 3-day period at which the resident was found wet. RESULTS Sixty-three (84%) of the residents completed the study. Among those completing the trial, the percent of checks wet went from 26.5% to 23.7% on placebo to 20.2% on active drug. These changes were statistically significant but not clinically meaningful. A clinically significant decrease in the frequency of incontinence, which we defined as a relative reduction in the percent of checks wet of > 33%, occurred in 20 subjects (32%) while on active drug and in 12 subjects (19%) while on placebo (P = .48 by chi-square). Twenty-five subjects (40%) met our "continence criteria" of an average of one or less wet per day while on active drug, and 11 subjects (18%) achieved this goal on placebo (P = .005 by chi-square). CONCLUSIONS Oxybutynin does not add to the clinical effectiveness of PV in the majority of nursing home residents with urge type urinary incontinence. Selected residents may, however, become more responsive to PV while on oxybutynin. Our data are consistent with other studies of bladder relaxant medications in functionally impaired populations. New drugs and/or other interventions are needed for the large number of incontinent nursing home residents who do not respond well to PV.