A method of operating a hydraulic pump of a drive train of a motor vehicle having a transmission with a hydrodynamic torque converter and a engine, with the input speed of the hydraulic pump being adjusted depending on the speed of the engine. The input speed of the hydraulic pump is adjusted depending on the pump speed of the torque converter, which corresponds to the speed of the engine and depends on the turbine speed of the torque converter, such that when the pump speed of the torque converter is higher than the turbine speed of the same, the hydraulic pump is operated at a speed higher than the speed of the engine. When the turbine speed of the torque converter and the pump speed of the same equalize, the excessive increase in the input speed of the hydraulic pump is reduced in relation to the speed of the engine.