Photoluminescence spectra of CaWO 4 doped with Pr 3+ and Tb 3+ obtained at high hydrostatic pressures up to 315 kbar applied in a diamond anvil cell (DAC) are presented. The intensities of the luminescence from the 3 P 0 state of Pr 3+ and from the 5 D 3 state of Tb 3+ decreased with increasing pressure. At pressures greater than 50 kbar, the 1 D 2 → 3 H J transitions in Pr 3+ and the 5 D 4 → 7 F J transitions in Tb 3+ dominated the spectra. At pressures greater than 100 kbar, only emissions from the lower excited states were observed. At pressures greater than 150 kbar, luminescence from the 1 D 2 and 5 D 4 states also decreased with increasing pressure, and at a pressure of 315 kbar for CaWO 4 :Pr 3+ and 190 kbar for CaWO 4 :Tb 3+ , the emissions related to the Pr 3+ and Tb 3+ were quenched. These effects were related to the influence of impurity trapped excitons (ITEs) on the efficiency of the f–f emission in the Pr 3+ and Tb 3+ ions. Analysis of the emission spectra collected at different pressures allowed the energies of the ground states of the Pr 3+ and Tb 3+ ions with respect to the band edges of the CaWO 4 host to be estimated.