DCPA, bensulide, and diphenamid gave preemergence control of annual bluegrass in freshly tilled soil. Overseeding bermudagrass golf greens with cool season grasses reduced through competition the amount of annual bluegrass cover and provided a desirable putting surface. Annual ryegrass was more effective in this respect than red fescue. Bensulide and DCPA gave control of annual bluegrass and the rates required were partially offset by competing cool season grasses. The cool season grasses seeded one month after treatment were not affected by 5.6 kg/ha of bensulide whereas higher rates gave significant reductions in ground cover with cool season grasses. The margin of safety was not as great with diphenamid. Although bermudagrass growth was retarded in spring with the overseeded cool season grasses, the turf quality was maintained better with the transition from the overseeded grasses to bermudagrass than from the infested annual bluegrass to bermudagrass. Plant competition reduced the number of tillers and weight of annual bluegrass plants in the field and greenhouse studies.