Numbers of micro-organisms in soils from Wilkes Land varied widely. Bacteria, yeasts and Mamentous fungi occurred in all samples analysed and the numbers of bacteria were positively correlated with the numbers of yeasts, and with pH. Moss protonema and seven species of algae and cyanobacteria were also present and measurable amounts of chlorophylls a, b and c were extracted from some samples. Only a few sites, those with moist sandy or gravelly soils free of extensive moss or lichen cover, contained the single mite species recorded.