Background and Objectives : The objectives of this study were to assess the health-related quality of life (HRQL) of patients with heart failure (HF) and compare with that of some chronic diseases, and to compare HRQL of HF in Korean patients with that in other countries. Subjects and Methods : One-hundred three outpatients with left ventricular ejection fraction (LVEF) below 40% were interviewed to assess their HRQL. Their assessment of HRQL was measured by the Korean version of Medical Outcome Study-Short Form 36 (SF-36). SF-36 is a generic multidimensional instrument consisting of eight scale components representing physical functioning (PF), role limitations due to physical problems (RP), body pain (BP), general health perception (GH), vitality (VT), social functioning (SF), role limitations due to emotional problems (RE) and mental health (MH). SF-36 scores were converted to a scale of 0 to 100, a higher score indicating a better HRQL. Data of comparison groups were obtained from published studies. Results : HRQL in patients with NYHA class IV were lower than NYHA class II or III in all but one SF-36 scales, which was RE. All SF-36 scales except RE were significantly related to NYHA class. In contrast, LVEF was not significantly correlated with any of the SF-36 scales. In comparison with published data of patients with pacemaker, CABG or organ transplant recipients, patients with HF in this study scored lowest in five scales of SF-36, which were PF, RP, GH, VT and MH. Korean patients with HF scored lowest in two SF-36 scales, which were GH and MH, in comparison with Japanese, German, and English patients with HF. Conclusions : HRQL in patients with HF was reduced as NYHA functional class worsen. Korean patients with heart failure show particular weakness in GH and MH. These results indicate that patients with heart failure in Korea need interventions of emotional area.