Low temperature co-firable ceramics, Zn3Nb2O8, were developed by using V2O5 species as liquid phase sintering aids. Among the range of additives examined, 2 mol% V2O5 was observed to perform most satisfactory for acting as liquid phase sintering aids. The Zn3Nb2O8 materials can be densified in wide temperature range (850-1000 degreesC), resulting in similar microwave dielectric constant (K = 22.4) and the same high quality factor (Q x F = 67,500). Over firing (1100 degreesC x 4 h) causes marked degradation on Q x F-factor, without influencing the dielectric constant and density of the Zn3Nb2O8 materials. Microstructure examination reveals that the probable mechanism is due to the rigorous interaction between the V2O5 and Zn3Nb2O8 materials, forming a lossy layer surrounding the grains. (C) 2002 Published by Elsevier Science B.V.