The invention relates to a PTO brake control system. There is a need for an improved and safe PTO brake control system. A PTO may be put into a driven and a non-driven condition an is braked by a PTO brake. A PTO brake control system includes a vehicle speed sensor and an ECU for controlling the PTO brake. The ECU deactivates the PTO brake when the vehicle is stationary and the PTO is not driven. This allows the PTO to be manually rotated to facilitate coupling of the PTO to an implement.