In this study, the effect of B2O3 addition on the sintering behavior of 0-5-10% ZrO2 doped barium titanate based microwave dielectric ceramics were investigated. For this purpose, the powder mixtures consisting of BaCO3, TiO2 and ZrO2 were prepared by ball milling technique in alcohol using ZrO2 balls at 200 cycle/min for 20 h. The prepared powders were calcined at 900 degrees C for 2 h. Produced powders were mixed 0.5% B2O3 and 5% PVA and pressed as green body under the pressure of 100 MPa. The disc-shaped die-pressed samples were sintered at 1250 degrees C, 1350 degrees C and 1450 degrees C for 4 h. X-ray diffraction analysis showed that the main phases formed in the sintered samples are BaTiO3 and Ba(Ti1-xZrx)O-3. The scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to investigate microstructure of the sintered samples. The bulk densities of the sintered samples increased with the addition of B2O3 content due to the low number of pores trapped between the grains.