The phase composition and spectral-luminescent characteristics of yttrium partially stabilized zirconia (YSZ) crystals doped with Nd 2 O 3 and CeO 2 (ZrO 2 -Y 2 O 3 -Nd 2 O 3 -CeO 2 ) are studied. X-ray diffraction shows that YSZ ZrO 2 -2.5 mol %Y 2 O 3 -0.2 mol %CeO 2 -0.1 mol %Nd 2 O 3 , ZrO 2 -2.03 mol %Y 2 O 3 -0.435 mol %CeO 2 -0.334 mol %Nd 2 O 3 , and ZrO 2 -2.03 mol %Y 2 O 3 -0.653 mol %CeO 2 -0.111 mol %Nd 2 O 2 YSZ crystals contain two different tetragonal phases (transformable t and nontransformable t ). The spectralluminescent properties of these crystals indicate that Nd 3+ ions occupy sites mainly in the transformable (t) phase.