The Larsemann Hills provide a unique opportunity for studying the environmental impacts of four research facilities run by three nations (Australia, China, and Russia). Soil and water samples collected from the vicinity of each station approximately 10 years after their establishment were analysed for a variety of hydrocarbons, metals, and nutrients. Results confirm that hydrocarbon contamination is the most common impact of the stations. Nutrient enrichment of soil was identified within small areas of each station, and water samples obtained from several local tarns and meltpools revealed low-level contamination by metals and polyaromatic hydrocarbons (PAH). Faecal coliforms were present in intertidal pools adjacent to sewage effluent discharge but not in any other water bodies tested. The cumulative impact of the four facilities was an increase in the number of sites contaminated, rather than increased contamination at specific locations due to the additive effect of overlapping sources. The highest levels of contamination were extremely localised and the footprint of contamination arising from each of the facilities remained discrete from that of neighbouring stations. These data provide a baseline to compare environmental conditions at these locations in the Larsemann Hills before and after implementation of the Protocol on Environmental Protection to the Antarctic Treaty.