Alzheimer,s dementia is one of the most important disease in the elderly in neurological and psychiatric science and practice,connected to the biological ages of 65 or more, but rarely it could be seen and younger patients. According to the criteria of WHO, dementia means loss of memory and associated with other sensory probems: dysphasia, agnosia, apraxia, orientation problems, problems in making of daily decisions and other. Among dementias, Alzheimer,s disease has the most important role because it is the cause of 80 per cent of these diseases. In Croatia there are about 80,000 patients suffering of Alzheimrer,s disease, i.e. about 10 per cent of the whole elderly population. We think today that genetic factors play the most important role in a development of this disease. Those factors include APP (amyloid precursor protein) gene mutations on the 21-th chromosome, gene mutations for preseniline-1 on the 14-th chromosome, and a gene for preseniline-2 on the 1-th chromosome. It is connected to the accumulation of protein amyloid-B-peptide (Aβ) 42. This disease is more frequent int he elderly, with low education level, in those with head trauma, in females, and in persons sufferinf of prolonged stress situations. It is not possible to control the genetic component oft his disease. That is why we have to control some chronic diseases as are arterial hypertension, diabetes mellitus (type 2), hyperuricaemia, dyslipoproteinaemias, beside smoking habits and obesity. Mental and aerobic physical exercise should be at the first place of health activities, because it could delayed or to slow Alzheimer,s dementia. In a ner future we are expecting that genome analysis in personalized medicine will show us the right way about types of physical exercise.