Angle-resolved ultraviolet photoelectron spectroscopy has been used to study the electronic structure of a Si(110)2x3-Sb surface. The surface shows a semiconducting behavior with the highest occupied surface-state band observed around 1.8 eV below the Fermi level (E(F)). A second state is observed at Gamma at 2.2 eV below E(F) dispersing >2.0 eV towards higher binding energies along the [(1) over bar 10] and [(1) over bar 11] directions. A third state is observed along the [(1) over bar 11] direction around the M point. Surface differential reflectivity experiments showed no optical transitions up to an energy of 3.5 eV, indicating that the minimum energy position of the lowest empty band must be at least 1.8 eV above E(F).