A lack of information on economic values, especially non-market values, has contributed to wetland degradation in the Mekong River Delta. To fill this information gap, this study uses choice modelling to estimate biodiversity values of Tram Chim National Park in Vietnam. It is found that Vietnamese respondents are willing to pay for the wetland conservation. However, the willingness to pay estimates differ among sub-populations and are reduced by the use of a cheap talk script. Some issues of applying choice modelling, including questionnaire designs and survey methods are discussed in the context of a developing country.