Before shaping, Lu2O3 powders doped with different ZrO2 concentrations were synthesized by a simple combustion method and milled. The shaped green bodies were sintered at 1850 degrees C for 6 h in vacuum. The transmittance and microstructure of the resultant ceramics were characterized by spectrophotometer and SEM. The effects of ZrO2 concentration on the microstructure and optical property of transparent Lu2O3 ceramics were evaluated. When doped with 5 at.% ZrO2, the Lu2O3 ceramic showed the best optical transmission and the in-line transmittance reached 70% in the visible spectral region. The addition of ZrO2 was found effectively to prohibit grain growth and to remove residual pores.