An intense red-emitting NaY(MoO4)2:Eu3+ nanophosphor was developed using a hydrothermal technique. A highly pure and single-phase NaY(MoO4)2:Eu3+ nanopowder was obtained after sintering the as-prepared sample at 800 degrees C. The crystal structure and photoluminescence properties of this double molybdate were investigated. X-ray diffraction analysis showed that the NaY(MoO4)2 nanoparticles have a scheelite-type tetragonal structure, without mixed phases. Rietveld analysis provided the atomic coordinates and Mo-O-rare-earth angles. The morphology of the molybdate precursor was controlled by adjusting the synthesis conditions. The pH was found to play a crucial role in the particle size and morphology distribution. The crystalline powder phosphor exhibited intense and efficient red emissions attributed to efficient energy-transfer from MoO4(2-) to Eu3+. The chromaticity coordinates (x,y) of the NaY(MoO4)2:Eu3+ phosphor sample correspond to (0.662, 0.337). The NaY(MoO4)2:Eu3+ powder exhibited a deep-red emission under near-ultraviolet (UV) excitation, indicating a promising red phosphor for white-light-emitting diodes based on near-UV light-emitting diodes.