This study assessed whether three patients with Alzheimer's disease could learn to use urine alarms and caregivers' prompts to eliminate large urinary accidents. As soon as the patient began to release urine, the alarm system presented auditory and vibratory signals. In relation to those signals, the caregiver would prompt/encourage the patient to stop urinating and accompany him or her to the toilet to void. After urination, the caregiver provided the patient positive social attention. The results of the intervention showed that the use of the alarm system and caregivers' prompts was effective in helping the three patients reduce their large urinary accidents to zero or near zero levels. Self-initiated toileting, which was minimal during baseline, accounted for nearly 35%, 50% and 75% of the patients' toileting occasions during the intervention. Fifty-two caregivers, who participated in a social validation assessment of toileting approaches relying on alarm systems or timed toileting, seemed to find the former preferable for the patients, for the context, as well as for themselves. The implications of the findings for daily programs of patients with Alzheimer's disease and other dementias are discussed. (Contains 1 figure and 2 tables.)