A window blind for motor vehicle doors including a winding shaft arranged underneath the window's lower edge is provided. One edge of the blind sheet is fastened to the winding shaft and its other edge is attached to a pull bar. The pull bar is connected to at least one support rod that is arranged approximately at a right angle to the pull bar and projects into the body of the door. The support rod is guided in the door body and it is provided at its inner end with a dog. The dog is designed to cooperate with a dog driven by the window lifter, so that the window blind is also opened semiautomatically when the window is opened.