Under the new climate-change regime, electric vehicles (EVs) have received particular attention for their ability to help mitigate greenhouse gas emissions. The government is looking to implement a vehicle-to-grid (V2G) service for EV use. The present study estimates the economic value of a V2G service, adopting the contingent valuation approach. An online contingent valuation oriented survey of 1007 interviewees was conducted for deriving their willingness-to-accept for the service. The mean willingness-to-accept estimate was achieved as KRW 9821 (USD 8.83) per month, per vehicle; thus, the estimated annual benefit amounted to KRW 117,852 (USD 106.01). The findings can offer a valuable guideline for determining the economic feasibility of a V2G service. From a management perspective, the results can help primary stakeholders decide the optimal price level for that service.