Although N-glycosylation was first reported in archaea almost 40 years ago, detailed insights into this process have become possible only recently, with the availability of complete genome sequences for almost 200 archaeal species and the development of appropriate molecular tools. As a result of these advances, recent efforts have not only succeeded in delineating the pathways involved in archaeal N-glycosylation, but also begun to reveal how such post-translational protein modification helps archaea to survive in some of the harshest environments on the planet.