Pb(Zn1/3Nb2/3)O-3-based ceramics have been prepared by two different processing methods: conventional (PZN-C) and reaction-sintering (PZN-RS), The conventionally prepared PZN-based ceramics densified at lower temperatures (950 degrees C) than the reaction-sintered samples (1100 degrees C), but the perovskite/pyrochlore ratio was always higher in PZN-RS. The presence of a substantial amount of pyrochlore phase in PZN-C ceramics caused a decrease in the electrical properties, The maximum dielectric constant values in PZN-C ceramics were 10%-15% lower than those of PZN-RS, despite a similar average grain size, 7 +/- 0.2 mu m The temperature of the maximum of the dielectric constant (T-max) was lower than that expected from the mixing rule because of the possible formation of Ba-Nb clusters. The higher chemical homogeneity in PZN-RS ceramics is the main reason for the higher dielectric constant, T-max and electromechanical response, as well as for the lower difference between T-max and the depolarization temperature (T-d) and the lower diffusiveness parameter (delta).