Background: Cognitive prognostic awareness (PA) and emotional preparedness for a loved one's death are distinct but related phenomena. However, the distinction between these two concepts has not been studied in family caregivers. Objective: To examine whether these two concepts are distinct by comparing their evolution and predictors over cancer patients' last year. Methods: Agreement between emotional preparedness for death and cognitive PA was longitudinally evaluated for 309 family caregivers by percentages and kappa coefficients. Predictors of the two outcomes were evaluated by multivariate logistic regression models with the generalized estimating equation. Results: Agreement between family caregivers' emotional preparedness for death and cognitive PA decreased slightly (54.73%–43.64%) from 181–365 to 1–30 days before the patient's death, with kappa values (95% confidence interval) from −0.060 (−0.123 to 0.003) to 0.050 (−0.074 to 0.174), indicating poor agreement. Participants were more likely to report adequate emotional preparedness for death if they had financial sufficiency, more contact/communication with the patient, lower caregiving burden, and stronger perceived social support. Family caregivers were more likely to have accurate PA if they were 56–65 years old, the patient's adult child, and had more contact/communication with the patient and greater subjective caregiving burden. Conclusions/Implications: Family caregivers' emotional preparedness for death and cognitive PA were distinct, as supported by their poor agreement, lack of reciprocal associations, and two different sets of predictors. Health care professionals should facilitate family caregivers' accurate PA and cultivate their emotional preparedness for death by enhancing patient-family contact/communication and easing their caregiving burden to improve quality of end-of-life care.