To assess the economic value of pharmaceutical therapy with Kremezin, we investigated the maximum amount of willingness-to-pay (WTP) of patients with chronic renal failure (CRF) for a hypothetical effect of Kremezin in delaying the initiation of dialysis treatments. A face-to-face survey was carried out in a sample of 141 CRF patients from 2 dialysis centers, composed of 82 hemodialysis patients, 38 peritoneal dialysis patients, and 21 non-dialysis CRF patients. Using a bidding game method with a starting point of 320,000 Won, which is the average monthly out-of-pocket payment for dialysis treatment, we asked the study subjects how much they would pay per month to receive Kremezin therapy. The mean out-of-pocket monthly WTP for Kremezin was 310,000, 430,000, and 520,000 Won (p<0.05, repeated one-way ANOVA)) when Kremezin delays the initiation of dialysis treatments by 1, 2, and 4 years. Significant correlation between the respondent`s WTP and income (r=0.266∼0.368, p<0.05) confirmed the construct validity of the WTP instrument. Regression results showed that patients with a higher education, with diabetes as a major causes of CRF, and undergoing hemodialysis treatments tended to express higher WTP for Kremezin. The economic value of WTP from the perspective of patients varied from 310,000 to 520,000 Won depending on the effect size of Kremezin. The mean WTP was higher than 32,000 Won, only when the hypothetical effect of Kremezin in delaying the initiation of dialysis is for 2 years. This implies that Kremezin might be the preferred choice of therapy by CRF patients if it delays the initiation of dialysis treatment for at least 2 years.