To determine whether ultrasound-assisted prompted voiding (USAPV) care is more efficacious than conventional prompted voiding (CPV) care for managing urinary incontinence in nursing homes. Thirteen participating nursing homes in Japan were randomized to CPV (n = 7) or USAPV care group (n = 6). Residents of the allocated nursing homes received CPV (n = 35) or USAPV (n = 45) care for 8 weeks. In the CPV group, caregivers asked the elderly every 2-3 h whether they had a desire to void and prompted them to void when the response was yes. In the USAPV group, caregivers regularly monitored bladder urine volume by an ultrasound device and prompted them to void when the volume reached close to the individually optimized bladder capacity. Frequency-volume chart was recorded at the baseline and after the 8-week intervention to measure the daytime urine loss. The change in daytime urine loss was statistically greater in the USAPV (median, -80.0 g) than in the CPV (median, -9.0 g; P = .018) group. The proportion of elderly individuals whose daytime urine loss decreased by >25% was 51% and 26% in the USAPV and CPV group, respectively (P = .020). Quality-of-life measures of elderly participants showed no significant changes in both groups. The care burden scale score of caregivers was unchanged in the USAPV group (P = .59) but significantly worsened in the CPV group (P = .010) after the intervention. USAPV is efficacious and feasible for managing urinary incontinence in nursing homes.