BACKGROUND: The study focused on figuring out the present status and distribution of the underlying diseases of Korean terminally ill patients (TIP) who were on life-support care (LSC) by conducting a nationwide health care survey. METHODS: The authors of this study requested that the 308 nationwide hospitals that operate intensive care units answer a questionnaire that asked about the number of admitted TIPs and their underlying diseases at 12 Am, 22 July, 2009. The proportion of TIPs among all the admitted patients and the percentages of the TIP's underlying diseases were calculated. RESULTS: In a total of 83.1% of the eligible hospitals responded, the proportion of TIP was 1.6 of 100 admitted patients. Terminal cancer was the leading underlying disease in the TIPs (42.4%). Five % of the patients on LSC were brain dead. More TIPs were admitted in the national/public or university hospitals than in the private or non-university hospitals. CONCLUSIONS: Futile treatment seems to be administered to the TIPs in Korean hospitals. The quality of terminal care in Korean hospitals should be improved by the application of socially acceptable LSC guidelines. Timely government health plans, including hospice care, to improve the quality of palliative care should be launched and maintained.