Decision support systems (DSSs) are computerized systems, including models and databases, for decision-making purposes. In a precision agriculture (PA) framework, spatial and temporal requirements for DSSs are of particular importance but dealing with uncertainties and human aspects leading to adoption should not be dismissed. This chapter examines the key issues associated with deploying DSSs in PA before moving on to consider their human and social aspects. The chapter provides a number of detailed case studies on the application of DSSs, with an emphasis on nitrogen management. Finally, the chapter considers research options for DSSs to improve productivity in a PA framework, and looks ahead to future research trends in this area.