The inheritance of resistance to Russian wheat aphid Diuraphis noxia (Mordvilko), in two resistant barleys, Hordeum vulgare L., ASE/2CM//B76BB and 'Gloria/Come', was studied in the field and in the greenhouse. The resistant genotypes were crossed with susceptible genotypes 'Esperanza' and 'Shyri'. Resistance reactions of F1, BC1, and F2 plants, and individual F2 plant derived F3 families indicated that resistance in each genotype was controlled by the same single dominant gene.