A new facile synthetic route to produce a nitride-based red-emitting phosphor has been established. The (Sr,Ca)(2)Si5N8:Eu2+-based multicomponent phosphor was successfully synthesized from the stable SrCO3-CaCO3-Eu2O3-Si3N4 system by simple one-step heating at 1600 degrees C for 4 h in an unpressurized N-2 atmosphere. The synthesized (Sr,Ca)(2)Si5N8:Eu2+-based red broadband emitting phosphor exhibited the peak wavelength as long as 661 nm with a practically high external quantum efficiency of 60% under the excitation at 450 nm, while the coexisting secondary phase was inactive under the blue-light excitation, showing no detrimental effects on the photoluminescent properties. The enhanced red emission compared to the unmodified Sr2Si5N8:Eu2+ phosphor enables further improvement of the color rendering properties of the white light-emitting diodes for solid-state lighting applications.