RESUMO
The most common cause of dementia among the elderly is Alzheimer's disease. Given the increasing population of the elderly, achieving a screening tool with high reliability and validity is an essential need for all communities. The main objective of the project was to determine the Persian version of Clinical Dementia Rating Scale [P-CDR1]. Twenty subjects were randomly selected from among 150, 50-70 year old people, who were illiterate and not mentally retarded, residing in the nursing home; and they were given the Persian version of CDR scale [test]. After three months, the group was given the test again. The findings showed that from the specialists' standpoint CDR scale had acceptable validity, and the test validity was achieved 0.05 at the significant level with Cronbach's alpha and reliability coefficients 73% and 89%, respectively. CDR scale is a reliable instrument for evaluation of clinical dementia rating among the elderly in Iran. It can be used in screening dementia, Alzheimer, and diagnosis of the severity and stages of Alzheimer.