Herein, Cs2NaY1−xPrxCl6 crystalline scintillators have newly been fabricated and characterized. The crystals exhibited emission bands at ∼300 and ∼500 nm, which originated from the 5d-4f and 4f-4f transitions of Pr3+ ions, respectively, and the scintillation decay time constants were 19-29 and 170-370 ns, respectively. The former was attributed to the emissions from the 5d-4f transitions of Pr3+ ions, whereas the latter was attributed to the host materials. The light yields of these crystals were higher than those of undoped Cs2NaYCl6 crystals. The Cs2NaY0.4Pr0.6Cl6 crystal exhibited the highest light yield (7100 photons MeV−1), which is approximately four times higher than that of the undoped Cs2NaYCl6 crystal (1800 photons MeV−1).