Abstract: A method for welding two opaque elements of polymer material stable at high temperatures including the following steps: preparing a lower element of opaque polymer material which is stable at high temperatures and to which is added a carbon powder in such a manner that the lower element is capable of absorbing laser radiation, preparing an upper element of polymer material which is stable at high temperatures, laser-welding the lower element and the upper element by laser radiation passing through the upper element and bringing about the welding at the interface between the upper element and the lower element. The upper element is made, during its preparation, opaque with respect to visible radiation and transparent with respect to laser radiation by adding a pigment to the polymer material, the pigment which is of the mineral or organic type not modifying the properties of the polymer material, being transparent with respect to laser radiation and stable at high temperatures.