Equilibrium moisture values for relative humidities of from 31 to 93% were obtained for sunflowerseed, flaxseed, and soybeans. The hygroscopicity of whole sunflowerseed per se is practically the same as that of flaxseed, that of dehulled sunflowerseed is somewhat lower. Soybeans show a hygroscopicity curve quite different from that of flax and sunflowerseed. The differences in these curves are not explainable by either the oil or the ash contents of the seeds.