Fluid dynamics theory applied to the hydrocyclone flow field has progressed in past experimental and theoretical investigations from a two-dimensional Prandtl mixing-length turbulence modeling to the current level of three-dimensional large-eddy simulation (LES) and differential-stress approaches. The LES approach eliminates the explicit empiricism that is imposed in the kappa-epsilon model. Turbulence in hydrocyclones is anisotropic. Since only the subgrid scales are modeled in LES, the anisotropy is largely taken care of in this approach. This article presents validation of the LES model with laser-anemometry data collected on 75 mm and 250 mm hydrocyclones. Verification with experimental data on mass split, axial velocity, tangential velocity, root-mean-squared velocity, air-core profile, and size classification clearly stands as a proof that LES can be applied to even larger hydrocyclones.