Systems and methods for controlling an underground boring tool involve rotating the boring tool and sensing a parameter of boring tool rotation. The boring tool is also displaced along an underground path and a parameter of boring tool displacement is sensed. Various sensors monitor boring machine activities, boring tool location, orientation, and environmental condition, and geophysical and/or geologic condition of the soil/rock at the excavation site. Data acquired by these sensors is processed by a boring machine controller to provide closed-loop, real-time control of a boring operation. The controller receives the boring tool signal and other sensor signals in real-time and, in response, transmits control signals to each of the rotation and displacement units substantially in real-time so as to control one or both of a rate and a direction of boring tool movement along the underground path.