The machinery used in industrial applications, such as in agriculture, construction, and forestry, are increasingly equipped with digital tools that aim to aid the operator in task completion, improved productivity, and enhanced safety. In addition, as machines are increasingly connected, there are even more opportunities to integrate external information sources. This situation provides a challenge in mediating the information to the operator. One approach that could be used to address this challenge is the use of augmented reality. This enables the system-generated information to be combined with the user's perception of the environment. It has the potential to enhance the operators' awareness of the machine, the surroundings, and the operation that needs to be performed. In this paper, we review the current literature to present the state of the art, discuss the possible benefits, and the use of augmented reality in heavy machinery.