CaMnO 3 - δ perovskite samples were synthesised by two different methods: conventional solid-state reaction and the citrate route involving autoignition. The formation of a perovskite phase was significantly influenced by the synthesis and processing conditions: samples obtained by the citrate route have a less distorted structure. These materials are always more oxidised than those prepared by the ceramic route and consequently have a higher Mn + content. Moreover, they present the highest electrical conductivity values, which is explained by a less distorted structure.