Obtaining cheap, appropriate and timely information on vegetation will be essential for sustainable and economically viable management of grassland and forage swards in the future. Remote sensing (RS) offers new possibilities to monitor vegetation repeatedly and at large scale, but so far, only a few applications exist. This chapter describes the most important sensor types, reviews the developments in sensor performance over recent decades and identifies significant advances for grassland research and practice. The development of systems with complementary sensors is presented as a promising research area, which will help to overcome the limitations of single sensors and provide better information about grassland composition, yield and quality. Thematic maps of farm fields are suggested as the central outcome of RS and data analysis. These maps could represent the relevant grassland features and constitute the basis for various farm management decisions at the strategic, tactical and operational levels.