Diatoms are an important element of many polar marine microbial communities and particularly abundant in Antarctic lakes. However, few comprehensive studies, such as the study presented in this volume are available on Antarctic communities. The diatom floras encountered in surface sediment samples from 33 lakes of the Vestfold Hills, Antarctica are presented. 67 distinct diatom species were identified in these sediments. They include cosmopolitan, Southern Ocean, endemic Antarctic and new diatoms. Each species encountered is described and illustrated; autecological information on the species is included where possible. Epilimnion water chemistry of the lakes sampled was determined to investigate their influence on diatom distribution. The studied lakes span a very large range of salinities from 0.5 to 165 permil. The authors show that salinity seems to have a strong influence on the observed diatom taxa.