Mesoporous Eu2O3 microspindles have been prepared by a facile solution process followed by subsequent heat treatment. By adding urea stepwise and varying the reaction time, the dimension of the Eu 2O3 microspindles can be easily tuned from 250 × 100 nm to 900 × 400 nm. The products were characterized by X-ray diffraction, small-angle X-ray scattering, (high-resolution) transmission electron microscopy, scanning electron microscopy, N2 adsorption, and photoluminescence spectroscopy. The Eu2O3 samples exhibit a relatively broad pore-size distribution, and the wall of the pore is constructed by well-crystalline Eu2O3 nanocrystals with diameters of about 15 nm. A possible formation mechanism of the mesoporous microspindles was also discussed.