Abstract In this work, the effects of scandium introduction on the luminescence of yttrium scandium (Sc) aluminium garnet powders doped with ytterbium (YSAG: Yb 3+ ) were investigated. Based on photoluminescence (PL) and photoluminescence excitation (PLE) spectra we made conclusions about the influence of scandium concentration and location on emission properties of ytterbium ions in YSAG. On the one hand, an analysis of the data showed that the increase of Sc concentration leads to broadening spectral lines regardless of a location of scandium ions in the crystal structure. On the other hand, the photoluminescence intensity of ytterbium ions in YSAG is more sensitive to scandium in the octahedral site than to scandium in the dodecahedral site.