The estimation of evapotranspiration from remote sensing data may use different types of models. Direct estimates from thermal infrared data or indirect estimates using assimilation procedure and Soil–Vegetation–Atmosphere Transfer models have been proposed. In both cases, the combined use of remote sensing data in different wavelength domains is required in order to estimate parameters such as LAI, roughness, albedo and parameters related to soil and vegetation water status. In this paper, the main aspects of evapotranspiration estimation from remote sensing data are outlined (an application on the Alpilles site is also presented).