A patient positioning system and a rail for use in the system. According to one embodiment, the system includes first and second stationary rails arranged parallel to one another. First and second sets of mounting assemblies are used to fix the first and second stationary rails, respectively, to a ceiling. A traverse rail is slidably coupled to the stationary rails. The system also includes a harness for holding a patient and a motorized assembly for raising and lowering the harness, the harness being slidably coupled to the traverse rail. At least one of the first stationary rail, the second stationary rail, and the traverse rail is shaped to include a top wall, a bottom wall, a left wall, a right wall, a substantially open front, a substantially open rear, a first rib extending from the left side wall to the right side wall, and a second rib extending from the top wall to the first rib, the first rib and the second rib jointly dividing the interior of the rail into a pair of upper chambers and a lower chamber.