We apply a survey technique known as the contingent valuation (CV) method to estimate the economic value that patrons attach to reference desk service in an academic library. The CV method has been used in environmental economics for the past 30 years to estimate the value of environmental amenities. We argue that the appropriate measure of patron benefit from reference service includes use value (the usual benefit concept in the library literature) and option value (the benefit to potential users of knowing they have the option of using the services). Our survey population consisted of the students and faculty of the academic campus of Virginia Commonwealth University. We surveyed 382 students and faculty eliciting willingness-to-pay (WTP) for reference desk services: WTP to maintain existing hours, WTP to keep the desk open an additional 18 hours per week; and WTP to add 18.5 more hours (all hours the library is open). The 10% trimmed mean (a robust measure of central tendency) indicates that, on average, students are willing to pay $5.59 per semester to maintain current hours of the reference desk; instructional faculty indicate they are willing to pay $45.76 per year to maintain current hours. Given reasonable assumptions about the cost of service, students and faculty place a value on the current hours of reference desk service which exceeds the cost by a ratio of 3.8 to 1.