Directions for the use of the CROPWAT computer program are provided. CROPWAT is a program for IBM-PCs or compatibles to calculate reference evapotranspiration, crop water and irrigation requirements, and scheme water supply; to develop irrigation schedules under various management conditions; and to estimate rainfed production and drought effects. In part 1, directions on the various procedures of the program are provided: how to install and to set up the program on a computer system, how to print and how to manage the various data files. The procedures for the various program elements are explained, as well as the input of data, the concept of the calculations and the various printouts. In part 2, a detailed example on the use of CROPWAT for the planning and management of irrigation projects is provided. Adequate attention is given to the collection and processing of data for input in CROPWAT. Examples are given of the analysis of the printouts for planning, management and evaluation of irrigation systems. Adequate attention is given to demonstration of the various applications of the scheduling program in indicative irrigation scheduling, evaluation of irrigation practices, rainfed production and supplementary irrigation, and deficit irrigation. In the annexes the results of the various calculations are provided in a range of CROPWAT printouts.