The unsteady MHD Non-Newtonain incompressible casson fluid flow due to a porous rotating disk with a uniform angular velocity in the presence of an axial uniform magnetic field and a uniform electric field is examined. The Hall current is not considered in this paper. The governing equations of the problem are then reduced to non-linear ordinary differential equations by introducing suitable similarity parameters. The similarity equations are derived in such a way that one can see the effects of the angular velocity explicitly unlike the usual similarity transformation of rotating disk problems. Numerical solutions to the reduced non-linear similarity equations are then obtained by adopting shooting method using the Nachtsheim-Swigert iteration technique.