Aim of the paper is to investigate unsteady flow of a viscous, incompressible electrically conducting fluid through a porous channel filled with porous medium under the combined effect of transverse magnetic field and radiative heat transfer. The expressions for velocity and temperature distributions are obtained using successive perturbation technique, discussed numerically and shown through graphs. The expressions of skin-friction coefficient and Nusselt number at the plates are derived, discussed numerically and their numerical values for various values of physical parameters are shown through graphs.