In China, caregiving for cancer patients is primarily the responsibility of family members. This role often exposes family caregivers to the contemplation of mortality. Death anxiety among family caregivers may influence the care they offer to cancer patients. This study aims to evaluate the prevailing level of death anxiety among Chinese family caregivers of cancer patients and identify its influencing factors. This cross-sectional study followed the STROBE statement. A total of 220 family caregivers of cancer patients were recruited from a prominent tertiary hospital in southern China. The survey included a general information questionnaire, the Collett-Lester Fear of Death Scale, the Social Support Rating Scale and the Simple Coping Style Questionnaire. In addition to descriptive statistics, ANOVA, mean differences, correlations and regression analyses were computed. The average score for death anxiety among family caregivers of cancer patients was 104.27 ± 21.02. Death anxiety was negatively correlated with a positive coping style and social support. Multiple linear regression analysis revealed that marital status, death education, patients' fear of death and coping style accounted for 41.0% of the variance in death anxiety among family caregivers. Family caregivers of cancer patients experienced a moderate level of death anxiety. Individuals who were unmarried or divorced, lacked death education, had negative coping styles or cared for patients with fear of death tended to have high levels of death anxiety. Healthcare providers should act as credible educators to reduce caregivers' death anxiety by imparting positive coping styles and accurate knowledge and values about death so caregivers can provide high-quality care to patients.