Objective: To describe caregiver and patient characteristics that are associated with negative and positive reactions in family caregivers (FCs) of cancer outpatients. Methods: A total of 194 FCs completed the Caregiver Reaction Assessment (CRA) scale 6 months after start of new treatment in patients with breast, ovarian, colorectal, or head and neck cancer. Linear regression models were used to examine which caregiver characteristics (i.e. demographic, self‐efficacy and social support) and patient characteristics (i.e.