Successful minimisation of the gap between hypothetical and actual be-haviours requires to consider the dimension of individual social interaction in the decision process. While this dimension has been acknowledged to play an important role in the construction of private good preferences, however, in the context of public good, the role of social interaction has not been adequately examined. Therefore, to shed a light on the role of social interaction in shaping preferences toward public good, I conduct a contingent valuation (CV) study in which the respondents are enabled to have social interactions prior their willingness to pay (WTP) elicitation question. And in order to do this, I construct a sampling design where respondents are divided into three different groups, namely treated, untreated, and control groups. The respondents in the treated and untreated groups were allowed to interact/discuss with each other, within and across groups, prior to the WTP elicitation question. I find that treated and untreated respon-dents with social interactions have higher and significant likelihood to purchase the public good relatively to control respondents. While those who did not have interaction have a lower WTP for the improvement of waste management.