In August 1972 divers collected cores from the Central and Western basins of Lake Erie for microbiological analysis. The cores were sectioned and examined for sulfur cycle bacteria, nitrogen cycle bacteria, total heterotrophs, iron oxidizing bacteria, insoluble organic and inorganic phosphate solubilizing bacteria. Eh, nitrogen, organic carbon, and percentage moisture determinations were also made.Data from these cores indicate that offshore sediments, not directly influenced by land inputs, contain similar, homogenously distributed bacterial populations which vary less than one order of magnitude between the sediment surface and the 5-cm level.