A description and ecological interpretation of lichen communities occurring on high ground in the Cairngorms is presented. The area supports only a limited lichen flora but it is highly specialised; a quarter of the 134 species encountered are thought to have their main area of distribution in Britain on the Cairngorm plateau. The majority of these are associated with areas of late snow-lie from which Cladonia stricta, Lecidea griseoalra, Micarea viridiatra, Sporaslatia cinerea and Staurothele clopima, all new to the British Isles, were discovered together with two species still to be determined. The detailed zonation of lichens round a semi-permanent snow patch was investigated using a transect. Central areas of snow-beds are identified as receiving sites for nutrients and contain a proportion of basiphilous lichens. High wind speeds appear to restrict lichen distribution in certain saxicolous habitats; from several such sitesLecidea nigroleprosa new to Britain was collected. In Funcus trifidus heath and dwarf Calluna the occurrence of lichens is largely determined by the growth and decay of the dominant higher plants.