Dementia is one of the most important public health problems as a result of the rapid increase in the number of elderly persons worldwide. Improvement of prevention strategies and caring for people with dementia should be undertaken. We performed a door-to-door study to screen all subjects aged 50 years and older (n=4,329 of 33,285 inhabitants) in Al-Quseir city. The screening was performed by 3 neuropsychiatrists, using a modified form of the Mini-Mental State Examination. Suspected cases were subjected to case ascertainment according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, diagnostic criteria for dementia; full clinical assessment; psychometric assessment using Cognitive Abilities Screening Instruments, Hachinski Ischaemic Score, Instrumental Activities of Daily Living Scale and the Geriatric Depression Scale; neuroimaging (computed tomography and/or magnetic resonance imaging); and laboratory investigations for selected patients when indicated. The prevalence of dementia was 2.01% for participants aged 50 years or older and 3.83% for those aged 60 years or older. It increased steeply with increasing age to a maximum of 13.5% for those aged 80 years or older. Alzheimer’s dementia (48.3%) was the most common subtype, followed by vascular dementia (36.8%), dementia resulting from general medical conditions (11.5%), and last, dementia resulting from multiple etiologies (3.4%).