We have studied the atomic structures formed by monolayer coverages of Au and Ag on the Si( 11) surface using primarily the technique of Impact-Collision Ion Scattering Spectroscopy (ICISS). For the case of Au films annealed at 700' C, three different types of LEED patterns are formed depending on the fractional monolayer coverage: 5x 1, .hxio), and 6x6. The ICISS data reveal that all the three surfaces are structurally similar: the Au atoms reside above the Si(l 11) plane, most likely in threefold-hollow sites, and the different surfaces appear to be characterized by rows (5xl) or a honeycomb network (O13x'I and 6x6). In contrast, the Ag films deposited at elevated substrate temperature 4W&' C) 4ipla only a Ox LIED pattern for coverages ranging from 0.25 to 35 monolayers. A trimer model appears to be consistent with the low coverage Ag ICISS data rather than a honeycomb arrangement of the A atoms.