Lysimeters have been used extensively in the past to provide baseline information for development, calibration, and validation of evapotranspiration methods. This proceedings, ""Lysimeters for Evapotranspiration and Environmental Measurements"", includes all papers presented at the International Symposium on Lysimetry, held in Honolulu, Hawaii, July 23-25, 1991. These 49 papers cover a wide range of topics. While some describe the history and background of lysimetry, others discuss the design and operation of various types of electronic, mechanical, and hydraulic weighing lysimeters, drainage lysimeters, and lysimeters for environmental studies. The rest of the papers cover such topics as data acquisition systems, environmental requirements necessary for accurate measurement of evapotranspiration (Edt), and the development of Edt equations and cropping factors.