A gang-type lawn mower system comprises a main frame and a plurality of mower decks secured to the main frame. Mounted on the frame is a power source such as an internal combustion engine. A drive train is interconnected between the power source and each of the mower decks. Thus, each mower deck is driven by the single power source. Further, the frame structure includes a tongue that is adapted to be connected to a tractor. Therefore, in cutting grass, the frame structure is pulled over the ground and each of the mower decks, driven by the power source, cuts grass or other vegetation that passes under the mower deck. Additionally, each mower deck is pivotally connected to the frame structure about at least one pivot axis.