The rotating ring-disk configuration, consisting of a Pt disk and Si ring, was used to investigate light emission from porous Si in acetonitrile. The electroluminescence (EL) of n-type porous Si and the chemiluminescence (CL) of n- and p-type porous Si in the presence of an oxidizing agent in solution are reported. The EL and CL characteristics are similar to those observed in aqueous solution. No EL of p-type porous Si could be observed in the presence of a strong reducing agent, probably due to bandedge unpinning. The photon energy of the EL of n-type porous Si is in good agreement with that deduced from the relative positions of the redox energy level and the semiconductor bandedges