The biogeography of Antarctic lacustrine diatoms is incompletely known due in part to the absence of information from some important ice-free regions. In the first detailed study of the diatoms of the Bunger Hills, 29 species were identified in near-edge microbial mats of lakes ranging in salinity from fresh to 77‰. Most of the species present had previously been recorded in other East Antarctic coastal oases. The distribution and relative abundance of diatoms within the Bunger Hills were strongly influenced by salinity, but other factors, notably the characteristics of lakes in the immediate area of a particular lake, also played important roles. © Springer-Verlag 2006.