Background: Family caregivers of bedridden or homebound patients are at risk of adverse physical and psychological outcomes. There is a need for a culturally adapted and valid instrument for measuring caregiver burden in palliative care programs. Objective: To develop a reliable and valid instrument to measure the self-perceived burden of informal caregivers of patients with serious health-related suffering. Design/Setting: "Caregiver burden" was conceptualized based on literature review and in-depth interviews.