OBJECTIVES: Dementia is associated with high costs of national healthcare in European countries. Disruptive neuropsychiatric symptom (NPS) such as agitation and aggression (A/A), increase caregiver burden, lead to premature institutionalization and death, and increase dementia costs. The aim of this study is to estimate the incremental societal costs for Patients with Dementia (PwD) with A/A in both Community-Dwelling (CD) and long-term care (LTC) settings in 8 European countries. METHODS: This study uses data fromthe RightTimePlaceCare (RTPC) European project. Interviews using structured questionnaires are conducted with 2014 PwD and their primary informal caregivers. Direct and informal costs are estimated from a societal perspective. Resource utilization is assessed with the resource utilization in dementia instrument. Resource consumption is valued using unit costs for each country, the replacement cost approach (informal care) and retail prices (medication).To estimate incremental costs of A/A, costs for PwD with A/A are compared to costs for PwD without A/A in both settings. Special emphasis is placed on the main predictors of costs. RESULTS: CONCLUSIONS: A/A in PwD living at home or in LTC setting increase societal costs by 15%.