The bacteria on the gills of 7 species of freshwater salmonid fishes were examined qualitatively and quantitatively. Both wild and hatchery cultured salmonids were examined. The former were obtained from 12 different locations in British Columbia. Species of Pseudomonas and Cytophaga predominated on both groups of fish. The microflora of the wild fish also contained Aeromonas and members of the Brevibacterium–coryneform–Erysipelothrix group. The microflora of cultured fish was less varied. As many as 106 viable organisms/g wet weight of gill tissue were recovered.