The red-emitting fine La2Mo2O9:Eu3+ powder phosphors have been successfully synthesized using surfactant-assisted hydrothermal approach. After the addition of certain amounts of surfactant (polyethylene glycol, abbreviated as PEG) into the process, both the morphology and photoluminescence property of the phosphors were improved. The powder phosphors were fine (~1 μm) and mono-dispersive in appearance, and showed a strong red emission line at 615 nm under the excitation of blue light at 465 nm. As the molar ratio of n(PEG)/n(La+Eu) was adjusted to 1:1, the sample exhibited the optimum emission intensity, which reached about threefold in comparison with that of the identical composition sample prepared by conventional solid-state reaction. The fine powder phosphors may be potential candidates as red-emitting materials for white LED applications.