A significant challenge in virtually all caregiving studies is the measurement of burden, particularly within the specific context of palliative care. Existing tools in the caregiving field are not specifically designed for palliative care. A new tool, which specifically assesses family caregivers' (FC) burden within the palliative care context, was systematically developed and validated. This paper describes the steps taken to develop this tool and to examine its psychometric properties. The Caregiver's Burden Scale in End-of-Life Care (CBS-EOLC) is a 16-item self-report questionnaire. Internal consistency reliability: Cronbach's alpha = 0.95. Construct validity: Most inter-item associations were consistent with the conceptual framework that emerged from qualitative data analyses. Convergent validity: Interscale correlations: a) Zarit's Burden Interview (BI) = 0.72 (p