Alzheimer's disease is a common neurological condition, appearing as early as age 40 but increasing dramatically in incidence over age 85. Different genetic factors are at play, modified by events over a lifetime. Clinical diagnosis is possible through careful history taking with a reliable informant and a minimum number of laboratory tests. A relatively predictable natural history can be observed, with progression through stages of cognitive loss, functional impairment and behavioural disinhibition or apathy. New medications such as donepezil offer hope for improving or stabilizing symptoms. Such treatment can be administered by primary care physicians with experience in the diagnosis and management of Alzheimer's disease. Disease stabilization, or even prevention, may be possible in the future.