A method is provided for producing a decorative part that has a closed cross-section having an external visible side and that has at least two support parts to be connected along a connecting joint. The support parts are held spaced at a distance from one another such that a gap is formed between the edges of the support parts which adjoin one another at the connecting joint. The support parts are inserted in at least two halves of a molding tool. A reaction plastic is injected into the molding tool, such that the reaction plastic penetrates the gap. The support parts are moved toward each other such that the gap closes while the reaction plastic is still liquid. The support parts are fixed against each other in this position at least until the plastic has sufficiently cured so as to form a bond seam in the connecting joint.