Andhra Pradesh which is known as the “Rice Bowl” of India has a lot of development for the irrigation and water resource projects, for which accurate measurement of crop water requirement is required. To estimate the crop water requirement, evapotranspiration should be measured accurately. From many researches carried worldwide in the past revealed that FAO-56 Penman-Monteith method is the universally accepted method for estimation of evapotranspiration in any climatic conditions. This method requires huge data sets, therefore many empirical methods have been developed which require less numbers of inputs such as temperature based methods, radiation based methods, and mass transfer methods. In many places of the study area, the data required for the calculation of evapotranspiration by standard method are not available. Hence, there is a great area of interest for evaluating the best empirical method which is most suitable for these areas. So, here in this study an attempt is made to evaluate the best empirical method for semi arid regions of the study area. Four temperature based methods, four radiation based methods, four mass transfer methods and two simplified methods were proposed by Valiantza's for reduced data sets. A total of 14 methods were used in this study.