We report on the preparation, structure and scintillation properties of single crystal cesium hafnium chloride bromide (Cs2HfCl4Br2 or CHCB). The crystals were grown using a vertical Bridgman technique process. Single crystal X-ray diffraction showed that the as grown CHCB crystal structure was isostructural to Cs2HfCl6 crystals exhibiting the cubic K2PtCl6-type crystal structure. The Cs2HfCl6-x-Cs2HfBrx system is a solid solution with the lattice parameter of Cs2HfCl6-xBrx increasing linearly with x in the range 0 < x < 1 and following Vegard's law. The light yield was found to be 37,000 photons/MeV comparable to Cs2HfCl6 and an energy resolution of 4.5% at 662 keV. X-ray luminescence showed a peak with an emission centered at 423 nm. The principal decay time was found to be 1.78 mu s, which is over twice as fast as previously reported for Cs2HfCl6.