In order to develop dielectric ceramics with temperature-stable permittivity characteristics, perovskite BaTiO3-Bi(Zn1/2Ti1/2)O-3-NaNbO3 ceramic solid solutions were investigated with a particular focus on effects of BaTiO3 and NaNbO3 contents on the dielectric properties of ternary compounds. Keeping the ratios of the other two constituents constant, decreasing the BaTiO3 content leads to a broadening of the temperature-dependent permittivity maximum and a decrease in the overall permittivity. For compositions of constant BaTiO3 content, replacing Bi(Zn1/2Ti1/2)O-3 with NaNbO3 shifts the temperature of the maximum permittivity to lower temperatures (e.g., to -103 A degrees C for a composition of 70BT-5BZT-25NN) while maintaining a broad permittivity peak with temperature, which for the 50BT-25BZT-25NN composition also satisfies the X9R standard. Thus, the investigation of BT-BZT-NN compounds resulted in promising dielectric properties with broad temperature ranges of high permittivity, which is of interest for advanced capacitor applications.