BACKGROUND Behavioural disturbances in dementia are a common cause of excess morbidity, impairing the quality of life for both patient and caregiver. As part of a comprehensive approach to management, which includes a search for underlying causes and behavioural interventions, pharmacotherapy can be extremely helpful in alleviating symptoms such as agitation, aggression, and psychosis. METHODS This paper reviews recent studies that examine the neurochemical basis of these behavioural disturbances in order to provide a rationale for the various classes of psychotropics which have been used. RESULTS While neuroleptics have been the best-studied class of drugs to date, modest efficacy and significant potential side effects often limit their use. Newer atypical neuroleptics may be better tolerated, though controlled data have yet to be published. There is increasing support of the use of carbamazepine and antidepressants such as trazodone and the selective serotonin reuptake inhibitors (SSRIs). CONCLUSIONS Further controlled studies of all of these agents are required. In order to determine whether transmitter-specific or behavioural-specific targeted interventions truly provide a rationale for the effective pharmacotherapy of these disorders.