The 2D collimated Bonse-Hart USAXS instrument was used to study the anisotropic and hierarchical pore microstructures in freeze-cast lithium titanate (Li4Ti5O12). USAXS data with scattering vector q=0.0001Å-1 to 0.02Å-1 were collected at sample orientations from -10o to 190o. I vs. azimuthal angle polar data at q values of 0.0003Å-1, 0.0006Å-1, 0.001Å-1, and 0.005Å-1 were also collected. Six Li4Ti5O12 samples differing by salt and gel additives and lithium titanate particle size were measured. Samples are strongly anisotropic at low q (aspect ratio of 0.3 to 0.4) for intercolumnar porosity and mildly anisotropic at high q (aspect ratio of 0.8) for interparticle pores. Models suggests the pore microstructures are comprised of two large anisotropic populations: 1μm (Φ=0.77; SA=2.88m2/cm3) and 0.5μm (Φ=0.05; SA=0.35m2/cm3) and two small, relatively isotropic populations: 38nm (Φ=0.02; SA=1.38m2/cm3) and 14nm (Φ=0.16; SA=35.3m2/cm3).