Purpose/background: Accumulating evidence shows that bereaved family caregivers report elevated distress for an extended period, which compromises their quality of life. A first step in the development of programs to enhance bereaved caregivers' quality of life should be determining the needs they experience to manage the loss, and the needs that are not being satisfied. Thus, this study aimed to develop a new measure to assess unmet needs among bereaved family caregivers.; Method: The 20-item Needs Assessment of Family Caregivers-Bereaved to Cancer measure was developed and validated with bereaved cancer caregivers 5 (n = 159) and 8 (n = 194) years after the initial cancer diagnosis of the index patient, when stress in providing care to the patient was assessed.; Results: Exploratory factor analysis yielded two primary factors: unmet needs for reintegration and unmet needs for managing the loss. Bereaved caregivers who were younger and ethnic minority, and who had greater earlier perceived stress of caregiving, reported their needs were more poorly met (t > 2.33, p < .05). The extent to which bereaved caregivers' needs to manage the loss were not perceived as being met was a consistent and strong predictor of poor adjustment to bereavement at both 5- and 8-year marks (t > 1.96, p < .05), beyond the effects of a host of demographic and earlier caregiving characteristics.; Conclusion: Findings support the validity of the Needs Assessment of Family Caregivers-Bereaved to Cancer and suggest that interventions to help bereaved caregivers manage the loss by assisting their transition to re-engagement in daily and social activities will benefit caregivers by mitigating bereavement-related distress years after the loss.