Behavioral disturbances in dementias are relevant because they are very common, they worsen patients' medical and cognitive condition, increase the caregiver burden and accelerate the admission to nursing homes. The different behavioral disturbances in dementias can appear isolated, but in most cases, patients present a combination of disturbances producting one of two main syndromes the psychotic or the affective syndrome. Proper handling of these behavioral disturbances requires a correct charcterization of the syndrome, discarding medical or environmental causes and selecting the drug with the better effectiveness and safety profile for each patient. In spite of the important number of psychotropics available, there is not enough scientific evidence about their real effectiveness and security in patients with Alzheimer's disease. This article reviews recent advances in the treatment of most common and disruptive behavioral disturbances (Rev Med Chile 2005; 133: 1242-51).