This work aims to improve the outstanding thermal and mechanical properties of commercialized wholly aromatic polyamide fibers (i.e., aramids), by crosslinking the materials. The introduction of a reactive azide group into the polymer structure leads to functional aramids. Crosslinking processes can be easily performed using an inexpensive thermal treatment after fiber spinning with current spin production facilities. This work describes the strategy of crosslinking aromatic polyamides to increase the outstanding thermal and mechanical performances of these materials. The introduction of a reactive azide group into the polymer structure leads to a 3D network after transformation and upon heating. An important fact is that cross‐linking can be easily achieved with current aramid fiber production facilities.