Low-firing Bi2Mo2O9 thick films with a thickness of 15-20 mu m were screen printed on Al foils and alumina substrates by screen-printing technology. The phase evolution, morphologies, and dielectric properties of the thick films were investigated. The thick films showed a pure Bi2Mo2O9 phase at temperatures below 610 degrees C. A mixture of Bi2MoO6, Bi2Mo3O12, and Bi2Mo2O9 phases was found in the thick films sintered at 610 degrees C and higher temperatures. The Bi2Mo2O9 thick films on Al foils sintered at 645 degrees C showed excellent dielectric properties with a relative permittivity of 38 and a dielectric loss of 0.7% at 5 MHz. At the microwave frequency range from 5 to 19 GHz, the Bi2Mo2O9 thick films on alumina substrates sintered at 645 degrees C had a relative permittivity of similar to 35 and Q x f of similar to 12 500 GHz. It indicates that the Bi2Mo2O9 composition as potentially useful for low-temperature cofired ceramic using Al electrode.