In our current paper, we investigate the unsteady magnetohydrodynamic (MHD) Walter's-B viscoelastic flow past a vertical porous plate located within a porous medium. We have taken into account of chemical reaction changes and radiation effects. The governing PDEs without dimensions describing the field move have been mathematically solved employing a closed analytical method. The resulting profiles for temperature, concentration and velocity, will graphicallybe described and qualitatively discussed.