Lack of inversion symmetry at a metallic surface can lead to an observable spin-orbit interaction. For certain metal surfaces, such as the Au(111) surface, the experimentally observed spin-orbit coupling results in spin rotation lengths on the order of tens of nanometers, which is the typical length scale associated with quantum corral structures formed on metal surfaces. In this work, multiple scattering theory is used to calculate the local density of states (LDOS) of quantum corral structures comprised of nonmagnetic adatoms in the presence of spin-orbit coupling. Contrary to previous theoretical predictions, spin-orbit coupling induced modulations are observed in the theoretical LDOS, which should be observable using scanning tunneling microscopy.In the presence of time reversal symmetry [E(k, ↑) = E(−k, ↓)] and spatial inversion symmetry [E(k, ↑) = E(−k, ↑)], no spin splitting can exist since E(k, ↑) = E(k, ↓). At a metal surface, however, spatial inversion symmetry is violated, and a spin splitting can therefore occur, i.e., E(k, ↑) = E(k, ↓). The spin-orbit coupling in surface states was first observed by LaShell et al. 1 on the Au(111) surface using photoemission spectroscopy. The form of the spin-orbit interaction was found to be similar to the Rashba spin-orbit coupling 2 , which has been heavily studied in semiconductor heterostructures and quantum wells. Additional experimental 3,4 and theoretical 5,6,7 evidence have confirmed the presence of significant spin-orbit coupling on the Au (111) surface. Although such a spin-splitting should, in principle, occur on all surfaces, the magnitude of the spin splitting depends very strongly on the nature of the surface. For instance, spin-orbit coupling has never been observed on either the Ag(111) or the Cu (111) surfaces. This is due to the fact that the magnitude of the spin-orbit coupling is determined largely by the atomic spin-orbit coupling and the gradient of the surface state wave function at the nucleus 7 ; theoretical calculations, which accurately predict the observed spin-orbit coupling on the Au(111) surface, predict the spin-orbit coupling on the Ag(111) to be a factor of 20 smaller than the spin-orbit coupling on the Au(111) surface 6,7 , well outside the range of current experimental observation. In addition to the Au(111) surface, photoemission experiments have discovered a variety of other metallic systems with spin-orbit coupling, such as on the Bi surfaces 8 , which exhibit an even larger spin-orbit coupling than that found on Au(111).Although most experimental observations of spin-orbit coupling in surface states are from photoemission spectroscopy, scanning tunneling microscopy (STM) has been used to observe spin-orbit interference in a magnetic sample 9 and in nonmagnetic systems with very strong spin-orbit coupling, such as on the Bi(110) surface 10 and in Bi/Ag(111) and Pb/Ag(111) surface alloys 11 . However, previous theoretical work 5 has argued that scanning tunneling microscopy (STM) could not be used to observe the spin-orbit coup...