['There is a lack of information regarding geographical differences in the incidence and prevalence of dementia diagnosis according to the degree of aging of the population. The objectives of this study were to analyze the rate of dementia diagnoses, and to compare the dementia subtypes and the clinical characteristics of the patients depending on the degree of aging of their municipalities.', 'We used data from the Registry of Dementias of Girona (ReDeGi), containing the cases of dementia diagnosed in the memory clinics of the Health Region of Girona, in Catalonia (Spain), during 2007-2012. The municipalities were classified by a cluster analysis as aged or young municipalities according to their proportion of older people using population ageing indicators. The incidence rates of dementia diagnosis in each type of municipality were compared.', 'The ReDeGi registered 4,314 cases in the municipalities under surveillance. The clinical incidence of dementia was lower in aged municipalities (4.5 vs. 6.1 cases per 1,000 person-years aged 65 and over). Patients from young municipalities had an increased frequency of behavioral and psychological symptoms of dementia.'] Does rate of dementia diagnose according to the degree of aging of the population?