Six wheat/Agropyron intermedium addition lines are described on the basis of their phenotype and biochemical markers. An assessment of homoeology of each addition chromosome is made. Chromosome morphology, plant phenotype, isozyme and protein studies are compared with similar data for other wheat/alien addition lines and other members of the Triticeae. These comparisons give consistent results and it is concluded that addition lines L1, L2, L3, L4, L5 and L7 carry Agropyron chromosomes of homoeologous groups 7, 3, 1, 4, 5 and 6 respectively. This agrees with previously published work with one exception: the L5 chromosome belongs to homoeologous group 5 and not group 2 as proposed by Figueiras et al. (1986).