We report the controlled precipitation of PbS quantum dots (QDs) in glasses using multiple irradiation of the femtosecond laser pulses followed by thermal treatment. Upon the irradiation of femtosecond laser, PbS QDs were found to preferentially precipitate in the irradiated area after thermal treatment. Photoluminescence spectra showed PbS QDs in the irradiated area emitted at the long wavelength side, and transmission electron microscope images also confirmed that PbS QDs formed in the irradiated area were larger than those formed in the nonirradiated area. This controlled precipitation of PbS QDs can lead to the development of advanced optical materials.