Objective Preparing family surrogates for patient death and end‐of‐life (EOL) decision making may reduce surrogate decisional conflict and regret. Preparedness for patient death involves cognitive and emotional preparedness. We assessed the associations of surrogates' death‐preparedness states (that integrate both cognitive and emotional preparedness for patient death) with surrogates' decisional conflict and regret. Methods Associations of 173 surrogates' death‐preparedness states (no, cognitive‐only, emotional‐only, and sufficient preparedness states) with decisional conflict (measured by the Decision Conflict Scale) and heightened decisional regret (Decision Regret Scale scores >25) were evaluated using hierarchical linear modeling and hierarchical generalized linear modeling, respectively, during a longitudinal observational study at a medical center over cancer patients' last 6 months. Results Surrogates reported high decisional conflict (mean standard deviation = 41.48 6.05), and 52.7% of assessments exceeded the threshold for heightened decisional regret. Surrogates in the cognitive‐only preparedness state reported a significantly higher level of decisional conflict (β = 3.010 95% CI = 1.124, 4.896) than those in the sufficient preparedness state. Surrogates in the no (adjusted odds ratio AOR 95% CI = 0.293 0.113, 0.733) and emotional‐only (AOR 95% CI = 0.359 0.149, 0.866) preparedness states were less likely to suffer heightened decisional regret than those in the sufficient preparedness state. Conclusions Surrogates' decisional conflict and heightened decisional regret are associated with their death‐preparedness states. Improving emotional preparedness for the patient's death among surrogates in the cognitive‐only preparedness state and meeting the specific needs of those in the no, emotional‐only, and sufficient preparedness states are actionable high‐quality EOL‐care interventions that may lessen decisional conflict and decisional regret.