Calculations have been carried out to determine the time dependence of the residual photon dose rate around a high-energy proton accelerator. The development of the nucleon-meson cascade, the residual nuclei production, and the photon transport are calculated using Monte Carlo methods. Proton beams of 3- and 200-GeV and shields in the form of infinite cylinders of iron and heavy concrete are considered. Although the 3-GeV calculations are carried out with some exactitude, the results for the 200-GeV case mast be considered very approximate since the energy and angular distributions of the products from nuclear interactions in this energy range are not well known.