A dual-emission (UV/Visible) phosphor SrZrO3: Pr3+ was prepared by a high-temperature solid-state reaction method. The afterglow including ultraviolet (UV) and visible region which originated from self-trapped excitons and f-f transitions in Pr3+ was first observed after the short UV-irradiation. All as-prepared phosphors were studied systematically by X-ray diffraction, photoluminescence (PL) spectra, decay curves, long afterglow spectra (LAG), and thermoluminescence (TL) glow curves. The PL intensity and the performance of afterglow are dependent on the concentration of Pr3+ ions. The optimal concentration of Pr3+ ions for the brightest PL emission and the best afterglow characteristic were experimentally to be 0.5% and 0.4%, respectively. The different mechanisms for concentration quenching in both cases were discussed. A model was proposed on the basis of experimental results to discuss the mechanism of LAG in SrZrO3: Pr3+ in detail.