A method for smoothly and economically controlling the drive mechanism of a utility vehicle having a power take-off shaft (3), said drive mechanism comprising an engine (1), a transmission, a power take-off shaft clutch (2) and a controller (10). Said method comprises the steps of : a) on issuing the instruction for engagement of the power take-off shaft clutch (2) at a low rotational speed of the engine, engaging the power take-off shaft clutch (2) in a controlled manner, or automatically reducing the rotational speed of the engine (1) before engagement of the power take-off shaft clutch (2), respectively; b) when the power take-off shaft clutch (2) is completely engaged, automatically increasing the rotational speed of the engine by the controller (10) up to reaching the rotational speed of the engine required for the nominal speed of rotation of the power take-off shaft (3); and c) on disengaging the power take-off shaft clutch (2) again, automatically decreasing the rotational speed of the engine (1) by the controller (10).