The invention relates to a method of positioning service equipment of a coal-charging larry cart at charging ports of a coke oven, wherein a rail-guided larry cart is moved on the roof of a coke oven and is positioned at locations known by a machine control system and corresponding to charging ports in the oven roof in order to charge the oven chambers, and wherein then at least one piece of service equipment of the coal-charging larry cart is guided to the charging ports by horizontal biaxial positioning movements. According to the invention, an optical measurement method is used after each positioning of the larry cart to detect the coordinates of at least one marking that is applied to the oven roof and that has a fixed relationship with the center axis of a charging port within a measurement field that is predefined by the measurement method and to compare them with reference values that are stored in the machine control system for the marking. The deviations between the measured coordinates and the coordinates stored in the machine control system are determined for both axial directions. Differential values are then taken into account as correction values during the positioning movement of the piece of service equipment. The subject matter of the invention is furthermore formed by an apparatus for carrying out the described method.