Abstract Feeding trials were conducted with chinook salmon (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) to determine whether full-fat soybeans, commercial dehulled soybean meal, or solvent-extracted cottonseed meal could be used in an Abernathy diet as a partial replacement for fish meal with limited supplementation. Inclusion of full-fat soybeans in the diets fed to chinook salmon markedly reduced weight gain and increased mortalities. Commercial soybean meal inhibited gains in both species of salmon. Cottonseed meal was used efficiently as a replacement for fish meal in diets fed to chinook salmon but was not used as well by coho salmon at the highest level fed. The reason for the inadequacies of the soybean products was not determined.