Abstract: Background: Behavioral disturbances are commonly found in the Mild Cognitive Impairment (MCI) and during the early stages of the Alzheimer's disease. This review examines the typology and frequency of such behavioral symptoms. Method: Medline literature review until January 2019. Results: Although there is a vast and sometimes contradictory literature, most Authors agree on the following elements: 1) Behavioral symptoms are highly frequent; 2) Depression and anxiety are among its most common symptoms; 3) Symptoms appear in all types of dementia and also in animal models of the Alzheimer's disease. In fact, behavioral symptoms are so common that some Authors propose the concept of Mild Behavioral Impairment (MPI). Conclusion: Behavioral disturbances often represent the very first or one of the first signs of cognitive impairment among the elderly