This study contributes to the limited empirical literature on the applicability of non-market valuation surveys, including Choice Experiments, in developing countries. Non-market valuation as a policy tool in developing countries is frequently limited by the use of money as the numéraire. Thus, our study examines options for using a non-monetary numéraire to determine the willingness-to-pay (WTP) for environmental services. In a choice experiment in the Koshi basin of Nepal, respondents were divided into two sub-samples, and given monetary and non-monetary (labor) options to express their WTP. The results indicate that while some half the population is WTP in monetary terms for environmental services, this number goes up to three-fourths when asked to contribute in time instead of money. Similarly, estimated social benefits from environmental services are 1.44 to 2.20 times higher in labor hours relative to estimated benefits in monetary terms. This study also estimates that the shadow value of time to participate in watershed management activities is 79 percent of the market wage rate.