Cubic Ia (3) over bar Tm-Lu2O3 porous nanorods of similar to 45, mu m length and 90 nm diameter have been prepared with precise compositions through a soft hydrothermal route (i.e., autogenic pressure, neutral pH, and 185 degrees C for 24 h) by using chloride reagents. For these nanorods, room temperature excitation and photoluminescence spectra of Tm3+ multiplets related to the eye-safe F-3(4) -> H-3(6) laser transition at similar to 1.85-2.05 mu m are similar to those of bulk crystals. Room-temperature luminescence decays of H-3(4) and F-3(4) exhibit nonexponential dynamics analytically reproduced by the sum of two exponential regimes, which are ascribed to the different rates of nonradiative relaxations in defects at the surface and in the body of the nanocrystals, respectively. Measured fluorescence lifetimes tau, 200-260 mu s and tau similar to 2.3-2.9 ms for H-3(4) and F-3(4), respectively, in 0.2% mol Tm-Lu2O3 nanorods, are considerably larger than in previous nanocrystalline Tm-doped sesquioxides, and they are close to values of bulk sesquioxide crystals with equivalent Tm3+ content.