In this paper, the effect of inclination on hydrocyclone performance is studied using both computational fluid dynamics (CFD) and experimental methods. Experiments with water medium and the corresponding water-air two-phase CFD simulations in a 75 mm diameter cyclone are carried out at various inclined positions to the vertical plane. The two-phase CFD flow analysis shows that the water split to underflow decreases as the inclination increases, which is consistent with the experiments. The predicted flow velocity profiles were analyzed for different inclinations. An increase in the inclination results the air-core size reduction and reduced pressure drop profiles. Experimental classification also performed using the silica slurry. The experimental analysis shows the increased cut-size and the reduced water split with the inclination. Cross validation of inclined cyclone's CFD data is attempted with Electrical Resistance Tomography (ERT) and High speed video imaging experiments. The inclination effect on hydrocyclone flow field is further analyzed in terms of turbulence parameters; turbulent intensities, and radial RMS velocities. Turbulent dispersion of the particles is calculated using the CFD data and plotted by using a dispersion index formulation. Fish hook phenomena and possible mechanism of particle classification under the influence of inclination is also explained. Experimentally measured cut size and water recovery to underflow for 10 wt% silica slurry at various inclinations are compared with numerical predictions. Predicted efficiency curves are found in a close agreement with experiments for all the inclinations. (C) 2014 Elsevier B.V. All rights reserved.