Background A substantial number of family caregivers go through bereavement because of cancer, but little is known about the bereaved caregivers' long‐term adjustment. This study aimed to document levels of bereavement outcomes (prolonged grief symptoms, intense emotional reaction to the loss, depressive symptoms, and life satisfaction) among family cancer caregivers 3–5 years post‐loss and to investigate how self‐rated preparedness for the patient's death predicted those bereavement outcomes. Methods Family members participated in a nationwide survey for cancer caregivers 2 years after the relative's diagnosis (T1). Of those, 109 were identified as bereaved by 5 years post‐diagnosis (T2). Of those, 88 continued to participate at 8‐year follow‐up (T3) and provided valid data for the study variables. Caregivers' distress risk factors were measured at T1, satisfaction with palliative care and preparedness for the death of the patient at T2, and time since death of the patient at T2 or T3. Results Substantial numbers of family members (18% to 48%) displayed heightened levels of bereavement‐related psychological distress years after the loss. Hierarchical general linear modeling revealed that perceived preparedness for the death of the patient concurrently and prospectively predicted better adjustment to bereavement, independent of contributions of other factors studied. Conclusions Findings underscore the high prevalence of long‐lasting bereavement‐related distress among family cancer caregivers and the role of preparedness for the relative's death in the level of that distress. Findings suggest that psychosocial programs among caregivers focus on not only caregiving skills per se but also preparedness for the death of the patient. Copyright © 2015 John Wiley & Sons, Ltd.