Glass fibre-reinforced pipes are used in many applications, especially where corrosion resistance and the light weight have to be considered. This paper outlines a fracture mechanics approach for optimizing the geometry of an adhesive joint for glass fibre-reinforced pipes. The main tasks of this project are to optimize the coupler properties and the joint geometry. Cracks can originate at the coupler edges and at the interface between the two pipes. Fracture mechanics parameters are extracted from a finite element model and are used to optimize the joint length, coupler thickness, taper slope, coupler stacking sequence, and material properties.