Wetlands provide a variety of important environmental services including flood control, wildlife habitat, waste treatment, and recreational opportunities. Because most of these services are public goods, the value of wetland preservation cannot be directly obtained from market prices but may be estimated using revealed-preference or stated-preference methods. We estimate the value to local residents of protecting the Kuantu wetland in Taiwan using contingent valuation. Estimates are sensitive to question format, with estimates using a double-bounded dichotomous-choice format about three times larger than estimates using a single open-ended question. Using the open-ended format, the estimated annual mean household willingness to pay to preserve the Kuantu wetland is about US$21. Using the dichotomous-choice questions, the value is about US$65. These estimates suggest the total present-value willingness to pay to preserve Kuantu wetland is about US$200 million to US$1.2 billion (discounted at 5–10%).