The innovative core of modern precision agriculture is the use of agricultural machinery to perform precise, responsive field operations in large-scale mechanized precision crop production. Integration of autonomous functions into such machinery will endow it with capabilities which could be described as ‘intelligent’. These include perception, reasoning and control of operations in the field with the flexibility to achieve predetermined operational goals without human supervision. In this chapter, we review the current level of state-of-the-art intelligent agricultural machinery. We discuss the different kinds of automated guidance systems available, as well as path planning, automated actuation systems and implement controls. Finally, we discuss the prospects for creating increasingly autonomous systems and consider the potential implications of such technology.