Rare-earth-activated BaY(2)Si(3)O(10) (BYSO) phosphors were synthesized via a solid-state reaction. BaY(2)Si(3)O(10):Ce(3+) yields an indigo-blue emission peak at 404 nm according to excitation at 334 nm attributed to the Ce(3+) 4f-->5d transition. BaY(2)Si(3)O(10):Tb(3+) typically generates green emission peaks resulting from the 5D4-->7FJ transition. BaY(2)Si(3)O(10):Eu(3+) exhibits red emission peaks upon excitation at 393 nm. The quantum efficiency of these phosphors was found to be 53%, 55%, and 63% of commodity. The results in this work demonstrate that these phosphors with new compositions are good candidate luminescent materials for use in plasma display panels and light-emitting diodes, excited from VUV to UV.