This study examined the effect of polyvinyl alcohol (PVA) on the microstructure and permeability of freeze-cast porous alumina. The PVA addition was shown to have a significant effect on the pore size, with the trends in microstructure morphology and scale being qualitatively consistent with the effects of PVA addition on constitutional supercooling. The measured Darcian permeabilities were between 10−10 m2 and 10−12 m2. The permeability decreased as the PVA content increased and a significant fraction of the flow could be attributed to inertial effects.