Cancer is a disease that impacts not only the patient but also affects the entire family. Family members experience high levels of distress. Therefore, screening for cancer-specific distress among family members of people with cancer is important but relatively unexplored. This cross-sectional study aims to analyze the psychometric properties of a screening tool for family members of people with cancer. We examined the usefulness of the emotional thermometers burden version (ET-BV) in detecting caregiver emotional distress.