Goals of work The goal of this study was to investigate the utilization of and attitudes toward life-sustaining treatments (LSTs) at the end of life. Materials and methods We identified 4,042 families of cancer patients who had died at any of 17 hospitals in Korea during 2004. Among those, we analyzed the interviews provided by 1,592 (39.4%) primary caregivers. Only women who provided information in baseline and follow-up point could be included for internal comparison. Main results Most caregivers did not discuss with their patient the option of utilizing the intensive care unit (ICU; 92.7%) or cardiopulmonary resuscitation (CPR; 93.7%) to prolong an ending life. Logistic regressions indicated that the ICU was more likely to be utilized when patients experienced an unexpected medical problem before dying, discussed the ICU with the family caregiver, or were low-educated. CPR was more likely to be used if the patient died within 6 months of diagnosis or the family caregiver was <65 years old. Family caregivers more likely to use the ICU if placed in the same situation again were those whose patients had a higher monthly income or died within 6 months of diagnosis, low-educated, or had utilized the ICU. Conclusions Our findings underscore the importance of discussing LST with terminally ill patients based on adequate information.