The purpose of the literature review discussed in this article was to determine the effect of formal respite care on patients with dementia and their caregivers. Three computerized databases were searched for relevant English-language articles published from 1975 to 1994, and the bibliographies of retrieved articles were systematically reviewed for additional references. Five studies met the following inclusion criteria: original research; controlled trial of a defined respite intervention; sample including a dementia population; and at least one outcome measure relating to at least one of eight specified caregiver and patient variables. Four studies met validity criteria and were included for the review. There was little evidence that formal respite care has a significant effect on caregivers' burden, psychiatric status, or physical health; or on patients' cognition, function, physical health, or rate of institutionalization. However, given the small number of controlled studies found and their methodological and conceptual limitations, these data should be interpreted with caution.