OBJECTIVES:   Health utilities are preference-based measures for health states which are typically used in economic analyses to estimate quality-adjusted life years in order to model cost-effectiveness of different treatment options. Our aim is to report the standard SF-6D health utility scores in Japanese patients with CHC before treatment, during treatment with different regimens, and after achieving sustained virologic response (SVR-12).  METHODS:  Japanese patients were enrolled in clinical trials of sofosbuvir (SOF) used in combination with or without ledipasvir (LDV) and/or ribavirin (RBV). Patients completed the SF-36 questionnaire before treatment, every 4 weeks while treatment lasted, and then at week 4 and 12 follow-up visits. The SF-6D health utility scores were calculated from SF-36 using a non-parametric Bayesian algorithm. RESULTS:  494 patients with CHC (genotype 1 and 2) were enrolled: 19% with cirrhosis, 48% with a prior history of anti-HCV treatment. Of those, 153 received SOF+RBV, 170 received LDV/SOF+RBV, 171 received LDV/SOF for 12 weeks; the SVR rates were: 97%, 98% and 100%, respectively. Patients treated with the three regimens had similar SF-6D scores before treatment (p=0.87): 0.761±0.115; cirrhotic patients tended to have lower utility scores: 0.744±0.116 vs. 0.765±0.114 (p=0.1). During treatment with RBV containing regimen, patients experienced a decrement in their health utility score to 0.743±0.125 by the end of treatment (p=0.03), while patients treated with RBV-free LDV/SOF had their SF-6D scores improved to 0.792±0.128 after 12 weeks of treatment (p=0.0004). At post-treatment week 12, in patients who achieved SVR-12, the SF-6D scores were similar between the treatment regimens (p=0.36), and an average improvement of +0.014 points from the baseline level (p=0.01) was noted. In multivariate analysis, the use of RBV was independently associated with lower utility score during treatment (beta=0.047±0.012, p<0.0001).  CONCLUSIONS: Health utilities are lower in Japanese CHC patients and tend to improve after clearance of HCV infection.