Despite having provided the first example of a prokaryal glycoprotein, little is known of the rules governing the N-glycosylation process in Archaea. As in Eukarya and Bacteria, archaeal N-glycosylation takes place at the Asn residues of Asn-X-Ser/Thr sequons. Since not all sequons are utilized, it is clear that other factors, including the context in which a sequon exists, affect glycosylation efficiency. As yet, the contribution to N-glycosylation made by sequon-bordering residues and other related factors in Archaea remains unaddressed. In the following, the surroundings of Asn residues confirmed by experiment as modified were analyzed in an attempt to define sequence rules and requirements for archaeal N-glycosylation.