BACKGROUND AND OBJECTIVES: The increased prevalence of congestive heart failure (CHF) and disabled population with heart diseases has led, in 2000, to the establishment of Korean guidelines for grading disability in patients with CHF, but its usefulness has not been tested. The purpose of this study is to investigate the usefulness of the guidelines in grading disability and predicting the prognosis of patients with CHF. SUBJECTS AND METHODS: Between January, 1999 and March, 2003, 546 consecutive CHF patients were enrolled. Of these 546 patients, only 240 completed one year of follow up before the severity of disability was graded. They were classified into either the disabled or non-disabled groups according to the Korean guidelines for grading disability. They were also subdivided into severe CHF or non severe groups. Severe CHF was defined as a status greater than New York Heart Association class III or to those requiring frequent hospitalization, i.e. more than twice. The mortality and frequency of severe CHF between the disabled and non-disabled groups were evaluated. RESULTS: The prevalence of the disabled with CHF was 7.1% (17/240); one patient was graded in the severe disabled (grade 1), 4 in the moderate (grade 2) and 12 in the mild disabled (grade 3) groups. The mortality within the disabled group was higher than that in the non disabled group (8/17 vs. 1/223, 47.6% vs. 0.4%, p<0.001), but there was no difference according to the severity of disability (p=0.26). All survivors (9 patients) in the disabled group were classified with severe CHF, but 15 from 222 (6.8%) patients not classified in the disabled group also showed severe CHF stati. Half (8 patients, 50%) of the 16 whose total disability scores ranged between 15 and 19, 7 (21.2%) of the 33 with total scores between 10 and 14 were classified with severe CHF stati. CONCLUSION: The current Korean guidelines for grading of disability were able to relatively well predict the prognosis of CHF between the disabled and non disabled groups, but appeared too strict, in that some severe patients cannot be classified into the disabled group. Therefore, the current guidelines will either require modification following a large scaled study or the disability grades will have to be classified into more than 4 categories.