Purpose: Depression is the most common negative reaction among family caregivers of terminal cancer patients, persisting to post-bereavement. A modifiable factor associated with depression is mortality communication (i.e., caregiver-relative communication about illness and impending death). The purpose of this study was to examine the impact that mortality communication has on family caregiver's depression after bereavement, and to translate into Danish and examine the construct validity of the caregiver communication with patients about illness and death scale (CCID; Bachner et al. Omega 57(4):381-397, 2008). Methods: A total of 1475 Danish family caregivers (partners and adult children) of terminal cancer patients, in both general and specialized palliative care settings, participated in the study. Respondents completed questionnaires twice: during caregiving and 6 months after the death of their relative. Results: Results of the hierarchical regression analyses showed that discussing illness and death with one's ill relative was associated with fewer depressive symptoms after bereavement, adjusted for depressive symptoms in the final year of caregiving and socio-demographic characteristics. For both partners and adult children, each of the five CCID items contributed significantly to measurement of a mortality communication latent construct. Moreover, the relative contribution of all five items was consistent across caregiver groups supporting the reliability of measurement. Conclusion: As in Hebrew, Arabic, and English, the CCID can be used with confidence among Danish family caregivers. Mortality communication is a significant factor that may predict depressive symptoms while caregiving and also after the care recipient's death. This factor should be considered for inclusion in early family caregiver interventions.