Few articles and studies explore the sundown syndrome in Taiwan. However, the nurses and the caregivers may find the increased confusion and agitation among demented elderly during the late afternoon and the early evening hours, but most of them do not know how to deal with these problems. This article reviews the definition of the sundown syndrome, possible causes, and the nursing interventions based on the related studies. The nursing interventions include nursing assessment, light, activity, daytime nap, medication, environment, limited caffeine beverage, and careing methods. This article provides nurses and caregivers the needed practical information for taking care of the patients with sundown syndrome.