The study examines preference-based health-related quality of life (utility) for patients with heart disease in Japan. The study targeted patients with heart disease who were hospitalized at 3 hospitals. The study also used New York Heart Association (NYHA) classification for severity level of heart disease. Utility score was obtained by using EQ-5D-5L (EuroQol-5 Dimension-5 Level) in the evaluation for health-related QOL. In the study, an evaluation by therapist was also conducted to examine a difference in survey responses between patient himself/herself (Self) and proxy. For carrying out the study, we had ethical review at each hospital and received consent from each patient in writing. The study conducted regression analysis with use of STATA15.0 for investigating an influence on patient attributes in the statistical processing. The study received responses from total 174 patients with heart disease. The average age and gender was 68.7 ± 12.6 years old and 109 males (62.6%). The disease breakdown was 37 patients for heart failure, 43 patients for cardiac infarction, 10 patients for aorta dissection, 54 patients for valve disease, 18 patients for cardiomyopathy and 12 patients for other diseases. In NYHA classification, it indicates I=43, II=99, III=31, and IV=1. Utility score by Self in each NYHA classification was 0.84, 0.78, 0.64, and 0.57 respectively, and they were solely extracted as significant explanatory variables by regression analysis (p <0.001). In addition, for the responses by proxy, the score was 0.87, 0.78, 0.58, and 0.40 in Proxy 1 and 0.86, 0.76, 0.62, and 0.55 in Proxy 2 respectively. The study found a difference by NYHA in any of these responses. The study found a clear difference in utility score for NYHA classification. It was proved that EQ-5D-5L is an useful tool for preference-based health-related quality of life evaluation for patients with heart disease.