Psychosis and agitation often occur in the course of dementia and are a major source of patient disability and caregiver stress. For the common situation in which extrapyramidal (parkinsonian) motor dysfunction accompanies dementia, there is a therapeutic dilemma since the most frequently used drugs to treat the behavioral problems, neuroleptic antipsychotics, can worsen parkinsonism and have been associated with severe extrapyramidal reactions in some types of dementia. To date, the efficacy and tolerability of a promising alternative medication class to treat psychosis and agitation, namely atypical antipsychotics, has not been tested in patients with a primary dementia selected for coexisting parkinsonism.