Atmospheric pressure micro-discharges in porous media (MDPMs) potentially play an important role in plasma assisted fuel reforming, porous material surface treatment and high efficiency NOx removal from mobile and stationary sources. MDPMs are also of considerable interest to the biological applications of low temperature plasmas since all bio-tissues are to some degree porous media. To investigate the complex plasma-surface interactions in MDPMs, numerical simulations were performed of atmospheric pressure argon and air plasmas penetrating through an idealized packed bed reactor. The simulation platform was nonPDPSIM, a 2-dimensional plasma hydrodynamics model with radiation transport. Continuity equations for charged and neutral species, and Poisson's equation are solved coincident with the electron energy equation with transport coefficients obtained from solutions of Boltzmann's equation. The photon transport is based on a propagator or Green's function method which accounts for view angles and obstructions. The idealized packed bed is 5 mm thick and placed between two planar electrodes separated by a 7 mm discharge gap. The packed bed consists of dielectric rods (ε/ε0 = 4–400) producing a characteristic pore size of about 100 μm. The applied pulsed voltage is between 10–20 kV of either polarity.