Natural convection with Soret and radiation effects in a binary fluid saturating a horizontal porous layer under the influence of magnetic field is investigated. Adopting the Rosseland approximation for the radiative flux, the onset of instability is studied using the linear stability analysis. The result shows that the radiation absorption parameter delayed the onset of instability with higher values leading to greater stabilization of the system. The Soret parameter has significant effect on convective instability and this is discussed. In the absence of the magnetic field, the effects of the results obtained are more significant. Effects of other governing parameters are quantitatively discussed.