The dielectric properties of (Ta2O5)(1-x)(BN)(x) polycrystalline ceramics are reported for 0.0 < x < 0.25. Measurements were made at 1 MHz and temperatures between 0 and 100 degrees C. The dielectric constant is moderately enhanced in the high temperature tantalum oxide phase at low BN concentrations; it then decreases to an essentially composition-independent value at higher concentrations where the low temperature form of tantalum oxide is stabilized. In the low temperature form, above x = 0.05, there is a significant decrease in the temperature coefficient of the dielectric constant with increasing BN content.