The performance of a resonator incorporating a ceramic depends strongly on the dielectric properties of the ceramic. This paper discusses the measurement of these properties using the coaxial resonator method at high UHF frequencies. It is possible to calculate the dielectric constant with an accuracy better than 1%. If the conductivity of the metal coating on the resonator is known, it is also possible to calculate the loss tangent of the ceramic core. The measured Q 0-values, which depended on losses in both the silver coating and the barium nonatitanate dielectric of the λ/4 resonators, were compared with the theoretically calculated maximum values, on the basis that the ceramic is lossless and the conductivity of the coating corresponded with that of bulk silver. Typically, 70–90% of the theoretical maximum values were attained. The loss tangent of the Ba 2Ti 9O 20 ceramic was between 1 × 10 −4 and 2 × 10 −4 at 1 GHz. The temperature coefficient of resonance frequency was 4 ppm °C −1. Measurements yield useful data suitable for practical design purposes. In addition, the dimensions of the resonators are small, ranging from a few millimetres to a few centimetres, depending on the frequency, dielectric constant, and desired Q 0-value. The method can be used as a quality control technique for the ceramic manufacturing process.