This paper aims to discuss the assessment of oral health and nursing care for the elderly with dementia. To achieve the goals of early detection, early prevention and proper nursing strategies, an effective evaluation on the oral health conditions of the elderly with dementia is required. The elderly with dementia may be admitted to the nursing institutes along with impaired cognition, emotions, living abilities or even with the existence of problematic behaviors due to the progression of the disease. In addition, problematic behaviors among the elderly with dementia may be caused by poor oral health-induced negative mood. Therefore, novel oral health assessment scale assessment methods, reality orientation therapy, and proper brushing step flowchart as well as nursing strategies for the elderly with dementia in nursing homes are necessary. The development of the evaluation and nursing strategy will be beneficial to the management of oral health for the elderly with dementia residing in nursing institutes.