The invention relates to a method and a device for aligning the eyelets of harness elements in weaving machines, enabling the eyelets position in a harness element to be precisely determined and changed if required. A sensor is provided which traverses the plane of the eyelets and detects the position of the latter. Once the position has been detected, it can be changed by longitudinally displacing the harness element. According to a preferred second configuration for the implementation of the invention, an integral element carries out both heald hook centering and thread eyelet detection.