All-inorganic Cs 4 PbI 6 single crystals (SCs) is emerging scintillators for radiation detection. In this study, we report on the X-ray scintillation properties of Cs 4 PbI 6 SCs at the temperature range of 50-290 K. The temperature-dependent radioluminescence (RL) spectrum and decay time were investigated. It was found that the RL spectra show very pronounced temperature-dependent changes in the overall shape. The RL intensity increases with a decrease in the temperature under X-ray excitation. The emission bands at 318, 360, and 554 nm are attributed to the near-band-edge emission in Cs 4 PbI 6 SCs, the 3 P 1 → 1 S 0 transition of the Pb 2+ ion, and the emission of δ-CsPbI 3 aggregates dispersed in the Cs 4 PbI 6 SC matrix, respectively. With decreasing temperature, the fast and slow decay times tend to slow down and are estimated to be 46.0 ns (33.22%) and 820 ns (66.78%) at 50 K, which are far superior to that of the common cryogenic scintillator. These cryogenic scintillation characteristics of Cs 4 PbI 6 SCs demonstrate its potential for cryogenic detection.