— Abundant and consistent wind resource of deep water ocean have attracted offshore wind energy industry to look for the possible expansions and adoption of various oil and gas floating platform technologies. This has compelled the industry to venture in to floating offshore installations for wind turbines. The floating installations lead to complex rotor motions in 6 degrees of freedom. The current study focuses on the dynamic effects of the platform pitching motion on the rotor aerodynamics for OC3 phase IV case 5.1 with modified wave height. High fidelity CFD (Computational Fluid Dynamics) software was employed along with semi empirical tool, FAST developed by NREL, USA by assuming the wind turbine as a rigid body. The hydrodynamic effects leading to the pitching motion of the turbine platform are obtained from FAST. These pitching motions are coupled with the rotating blades to study transient flow behaviors using CFD. The results are compared with the standard BEM based methods having modified Prandtl tip loss factor. The results show that the increased wave height induces very high velocity and acceleration of the platform motion and thereby on the rotor plane. Morever this confirms that the turbine is operating both in windmill and turbulent state under such conditions. BEM validity with Glauert correction and validity of tip loss model is to be further assessed for the application of floating offshore wind turbine performance and design predictions.