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Soils of the McMurdo Dry Valleys are among the most extreme terrestrial environments, hosting low-diversity food webs of microbes, protozoa, and metazoan invertebrates. Distribution of soil invertebrates, particularly nematodes, is related to the highly variable soil geochemistry of the valleys. Bull Pass is a glacially carved area within the McMurdo Dry Valleys where a broad range of geochemical conditions occurs along a continuous soil gradient. This site provides the opportunity to investigate how soil geochemistry controls nematode distribution on a local scale, and to establish correlations that may also be relevant at regional scales. At Bull Pass, two nematode species were present, with the dominant Scottnema lindsayae occurring in >30% of the samples. There were significant negative correlations between live nematode abundance and soil nitrate concentration and salinity, consistent with experiments showing strong salinity effects on nematode survival. A logistic regression model based on data sets from across the McMurdo Dry Valleys showed a strong negative relationship between soil salinity and the probability of live nematodes occurring. Soil chemistry and nematode distribution from the Bull Pass transect are compared with model results and suggest that the larger-scale distribution of nematodes across the McMurdo Dry Valleys may be reflected in the smaller-scale chemical and biological gradients at Bull Pass.