Objectives. Given the national interest in progressive dementia, we estimated expenditures incurred in caring for dementia patients who live at home. Methods. Primary caregivers of 264 patients from a university-based memory disorders clinic were interviewed at baseline and asked to keep service use diaries for 6 months; 141 caregivers who returned the diaries are the focus of this report. We examined both formal and informal services (distinguished by whether money was exchanged) and associated expenditures. Results. Neither caregivers returning diaries nor their patients differed at baseline from those not returning diaries and their patients. Expenditures incurred over 6 months were extensive for both formal ($6986) and informal ($786) services. Out-of-pocket expenditures were high (e.g., in-home companion or sitter, adult day care, visiting nurse). Multivariable analyses indicated that patients with more severe symptoms of dementia and families with higher incomes reported significantly higher expenditures. Conclusions. The expense of caring for patients with progressive dementia living at home may be higher than previously estimated and frequently involves expenses paid directly by patients and their families.