Abstract: With the objective of simplifying the splicing of optical fibres and obtaining a very high degree of accuracy in the positional setting of the fibre ends prior to splicing the ends together fully automatically, the relative positions of the fibre ends are determined with the aid of laser light diffraction. By illuminating the fibre ends (1, 2) with laser light (3) and studying the image of the diffraction pattern on a display screen (6), which pattern can be related directly to the perpendicular distance between the fibre ends and the relative offset between the geometric axes of the ends, it is possible to determine the distance between the fibre ends by direct image analysis. A suitable splicing distance between the gap between the fibre ends can then be adjusted automatically to a value suitable for splicing, with regard to fibre material and fibre dimensions.