We have investigated Ce3+ : Y3Al5O12(YAG) as a model system for a 5d‐4fsolid‐state tunable laser. This system has been chosen since YAG has been extensively studied as a laser host and good quality crystals are readily available. Despite providing apparently adequate conditions to achieve stimulated emission, we were unable to detect laser action in Ce3+ : YAG. We find, however, strong excited‐state absorption in this material at the wavelengths of its fluorescence and we report on this excited‐state absorption (ESA) here. This self‐absorption may explain the failure of all attempts to obtain stimulated emission in this material and has serious implications for any attempt to develop a 5d4fn−1‐4fnlaser.