Red-emitting (Gd1-x-yCaxEuy)(2)W2O9-x phosphors (0 <= x <= 0.05, 0.05 <= y <= 1.00) were synthesized in a single phase form by conventional solid-state reaction. These phosphors exhibited excellent luminescent efficiency at excitation wavelengths of 394 and 464 nm, and the emission intensities were successfully enhanced by Ca2+ doping into the Gd2W2O9 lattice. The highest red emission intensity was obtained for (Gd0.58Ca0.02EU0.40)(2)-W2O8.98, and the emission intensities of this phosphor under excitations at 394 and 464 nm were 15.2 and 29.1 times higher, respectively, than those of a commercial (Y0.98Eu0.02)(2)O2S phosphor.