An anomalous positive temperature coefficient of electrical resistivity (PTCR) was investigated in three phase ceramics within the Zn-Ti-Ni-O system. The ceramics studied consisted of randomly dispersed constituent phases ZnOSS, NiOSS, and (Zn,Ni)(2)TiO4. It was found that although the pure constituent phases exhibit a NTC character, the multiphase ceramics exhibit a PTCR effect, with a maximum resistivity in the rho-T dependence at about 300 degrees C. The PTCR effect observed was about two orders of magnitude.