Systems and methods for making and using sliding counterbalanced C-arm positioning devices are described. In such systems and methods, each C-arm positioning device includes a C-arm X-ray device, a linear bearing rail, a linear bearing block, and a counterbalance mechanism. Generally, the C-arm is connected to the linear bearing block, which, in turn, is slidably coupled to the bearing rail to allow the bearing block and C-arm to slide up and down on the rail. The counterbalance mechanism can apply a force to the bearing block to counterbalance the weight of the C-arm and the bearing block. Thus, the described C-arm positioning device can allow a user to easily raise or lower the C-arm with relatively little effort. While some implementations of the C-arm positioning device are connected to mobile support structure, other implementations of the C-arm positioning device are mounted to a fixed support structure. Other implementations are also described.