The Pannariaceae of the montane regions of New Guinea contain 37 species in nine genera. Ten species are endemic, mostly from the subalpine zone. The following species are newly described: Fuscopannaria cacuminum, F. venusta, Pannaria tenuis (from Borneo), Parmeliellafoli- icola, P. laceroides, P. montana, P. nitida, P. pannarioides, P. piundensis and Psoroma filicicola, and two new combinations are proposed: Degelia lecideola (Zahlbr.) (Java) and Pannaria papuana (Apt- root & Diederich) (new to Borneo). Pannaria andina P. M. Jorg. & Sipman and Pannaria aff. rubig- inella P. M. Jorg. & Sipman are reported as new to Papua New Guinea, as well as Parmeliella hawai- iensis H. Magn.; the former two and Pannaria prolificans Vain, are also new to Borneo and part of a shared element between these disjunct, very high mountains. Parmeliella endomilta (Vain.) Makhija & Adawadkar (syn. nov. Parmeliella endoferruginea Aptroot and Parmeliella pannosa var. erythro- cardia Müll. Arg.) is new to Borneo, Indonesia, Madagascar and Mauritius, Parmeliella philippina (Vain.) P. M. Jorg. new to Java and New Guinea, and Parmeliella polyphyllina P. M. Jorg. new to the Philippines. The origin of the Pannariaceae in this region is predominately paleotropical, mainly Aus tralasian, but at high altitudes there are boreal, subantarctic and Andean elements, the latter being most intriguing.