A method of reducing wind induced vibrations of a wind turbine tower of a wind turbine system, wherein the wind turbine system comprises: - the wind turbine tower, - a sensor arrangement for sensing vibrations of the wind turbine tower, - a nacelle mounted to the wind turbine tower via a yaw bearing, - a control system for controlling yawing of the nacelle relative to the wind turbine tower, and wherein the method comprises: - sensing a vibration of the wind turbine tower using the sensor arrangement, - providing an input for the control system in response to the vibration of the wind turbine tower as sensed by the sensor arrangement, - providing an output by the control system based on the input, and - yawing the wind turbine nacelle based on the output from the control system to reduce wind induced vibrations of the wind turbine tower, and wherein after the nacelle has yawed a given angle from a first yaw position to a second yaw position the yawing of the nacelle is stopped at the second position for a first time period, the vibrations are sensed, and a decision of if to yaw further is provided in response to the sensed vibrations at the second yaw position, wherein, when the method is applied, the wind turbine system includes a lower number of blades than when the wind turbine system is completely installed. - the wind turbine tower, - a sensor arrangement for sensing vibrations of the wind turbine tower, - a nacelle mounted to the wind turbine tower via a yaw bearing, - a control system for controlling yawing of the nacelle relative to the wind turbine tower, and wherein the method comprises: - sensing a vibration of the wind turbine tower using the sensor arrangement, - providing an input for the control system in response to the vibration of the wind turbine tower as sensed by the sensor arrangement, - providing an output by the control system based on the input, and - yawing the wind turbine nacelle based on the output from the control system to reduce wind induced vibrations of the wind turbine tower, and wherein after the nacelle has yawed a given angle from a first yaw position to a second yaw position the yawing of the nacelle is stopped at the second position for a first time period, the vibrations are sensed, and a decision of if to yaw further is provided in response to the sensed vibrations at the second yaw position, wherein, when the method is applied, the wind turbine system includes a lower number of blades than when the wind turbine system is completely installed. - sensing a vibration of the wind turbine tower using the sensor arrangement, - providing an input for the control system in response to the vibration of the wind turbine tower as sensed by the sensor arrangement, - providing an output by the control system based on the input, and - yawing the wind turbine nacelle based on the output from the control system to reduce wind induced vibrations of the wind turbine tower, and wherein after the nacelle has yawed a given angle from a first yaw position to a second yaw position the yawing of the nacelle is stopped at the second position for a first time period, the vibrations are sensed, and a decision of if to yaw further is provided in response to the sensed vibrations at the second yaw position, wherein, when the method is applied, the wind turbine system includes a lower number of blades than when the wind turbine system is completely installed.