Methods of measuring visitor expenditures are discussed in this article. One approach uses a diary format, with the visitor recording expenditures as they happen. A second approach has visitors fill out an expenditure survey form just prior to departure, while a third involves surveying visitors after their return home. This article discusses the two methods used by the Hawaii Visitor's Bureau (HVB) in 1974. HVB's annual survey uses a questionnaire mailed to a selected number of visitors after their return home. In 1974, HVB also conducted a special survey where visitors kept a running account of expenditures as they occurred. Results from these two surveys are compared and sources of differences identified.