Infrared and ultraviolet absorption spectra arising fromf→fandf→dtransitions of Ce3+in YAlO3crystals are presented and used to derive the 4fand 5denergy levels. Excitation and fluorescence spectra of 5d→4femission are also reported. The 5dfluorescence has a decay time of 16 nsec and a radiative quantum efficiency of near unity at 300 °K. Possible use of Ce3+as a sensitizer for rare‐earth and iron‐group ion fluorescence in YAlO3is surveyed; included is an investigation of energy transfer in a Ce, Nd, Cr‐codoped crystal.