The purpose of this paper is to inspect the unsteady MHD mixed convective Couette flow of viscous dissipative fluid in a vertical channel filled with porous material. The steady state analytical solutions of temperature, velocity, frictional force and heat transfer rate are obtained using the Homotopy perturbation method (HPM). The implicit finite difference technique is used to solve the transient leading equations numerically. Plots and tables with the dynamic flow parameters and dimensionless variables are displayed. During this computation, it was found that raising the Darcy parameter (Da) and the mixed convection (Gre) parameters both push the fluid flow upwards, but increasing the magnetic field's values had the opposite effect (M). HIGHLIGHTS Effect of viscous Dissipation on unsteady MHD Mixed Convection Flow with Porous Material is investigated Increasing Darcy number improves the flow pattern Rate of heat transfer could be enhance by considering high values of Brinkman number GRAPHICAL ABSTRACT