Photoluminescence of erbium-implanted porous silicon is investigated. Room temperature 1.54 μm Er3+ luminescence is observed after annealing. The luminescence spectrum, annealing characteristics, temperature quenching, and the luminescence lifetime suggest that the Er3+ luminescence is mediated by photocarriers in the amorphous silicon matrix in porous silicon, and not related to the presence of the crystal nanograins.