In a process for the manufacture of an optical transmission element with several optical waveguides and with a slot element each surrounding the optical waveguides, a filling compound is applied intermittently to the optical waveguides in a liquid state. The optical waveguides are subsequently fed into an extruder, where the extruder forms a slot element around the optical waveguides. The filling compound expands only within the formed slot element, so that interstices present in the cross-section level of the transmission element are penetrated and several dry, compressible filling elements are formed, disposed about the respective optical waveguides. With the process according to the invention, the cross-section of the extruded slot element is not compromised during the manufacturing process.