Luminescence and scintillation properties of Cs2HfBr6 and Cs2ZrBr6 crystals were investigated using photoluminescence (PL) and radioluminescence (RL) spectroscopies. In the PL spectra, emission bands were observed at 435 and 525 nm for Cs2HfBr6, and at 530 nm for Cs2ZrBr6. Corresponding emission bands were observed for RL spectra. The scintillation decay time constants of the Cs2HfBr6 and Cs2ZrBr6 crystals were smaller than those of the corresponding Cs2HfCl6 and Cs2ZrCl6 crystals. The scintillation light yields of Cs2HfBr6 and Cs2ZrBr6 were estimated to be 61,500 and 37,200 photons/MeV, respectively, which are much higher than those of Cs2HfCl6 and Cs2ZrCl6 crystals.