Purpose: We conducted this study to evaluate the validity of the perception that awareness of their terminal prognosis and use of palliative care or nonuse of an intensive care unit (ICU) causes patients to die sooner than they would otherwise. Patients and Methods: In this prospective cohort study at 11 university hospitals and the National Cancer Center in Korea, we administered questionnaires to 619 consecutive patients immediately after they were determined by physicians to be terminally ill. We followed patients during 6 months after enrollment and assessed how their survival was affected by the disclosure of terminal illness and administration of palliative care or nonuse of the ICU. Results: In a follow-up of 481 patients and 163.8 person-years, we identified 466 deceased patients. Nineteen percent of the patients died within 1 month, while 41.3% lived for 3 months, and 17.7% lived for 6 months. Once the cancer was judged terminal, the median survival time was 69 days. On multivariate analysis, neither patient awareness of terminal status at baseline (adjusted hazard ratio [aHR], 1.20; 95% CI, 0.96 to 1.51), use of a palliative care facility (aHR, 0.96; 95% CI, 0.76 to 1.21), nor general prostration (aHR, 1.23; 95% CI, 0.96 to 1.57) was associated with reduced survival. Use of the ICU (aHR, 1.47; 95% CI, 1.06 to 2.05) and poor Eastern Cooperative Oncology Group performance status (aHR, 1.37; 95% CI, 1.10 to 1.71) were significantly associated with poor survival. Conclusion: Patients' being aware that they are dying and entering a palliative care facility or ICU does not seem to influence patients' survival.