OBJECTIVES: To estimate the Willingness to pay (WTP) per quality-adjusted life year (QALY) ratio with the stated preference data and compare the results obtained between chronic prostatits (CP) patients and general population.  METHODS: CP patients were recruited from two tertiary referral hospitals and the general populations were randomly approached in China at the beginning of 2009. WTP per QALY was calculated with a formula combining the subjects' own health-related utility and the WTP value. Two widely used preference-based health-related quality of life instruments, EQ-5D and SF-6D, were used to elicit utility for participants' own health. The monthly WTP values for moving from participants' current health to a perfect health described by ‘11111' status of EQ-5D were elicited using closed-ended iterative bidding contingent valuation method.  RESULTS: 268 CP patients and 364 participants from general population completed the questionnaire. We obtained four WTP/QALY ratios ranging from $4700 to $7400, which were lower than the proposed thresholds and published researches eliciting the preference for avoiding the risk of death. In addition, the WTP/QALY ratios from the general population were significantly lower than those from the CP patients and different determinants were associated with the within group variation identified by multiple linear regression.  CONCLUSIONS: Preference elicitation methods are acceptable and feasible in the socio-cultural context of an Asian environment and the calculation of WTP/QALY produced meaningful answers. The lower WTP/QALY elicited than published values and higher value from CP patients compared with the general population highlight the necessity of considering disease specific QALY in estimating WTP/QALY. Our results inferred that one threshold might not be enough to serve all decision-making under different situations. Further studies using the same methods to confirm whether the WTP/QALY value would be dissimilar among diseases with different impact on QoL would be needed.