Germanate apatites with composition La10–xGe5.5Al0.5O26.75–3x/2 have been evaluated for the first time as possible electrolytes for solid oxide fuel cells (SOFCs). Different electrode materials have been considered in this study, i.e. manganite, ferrite, nickelates and cobaltite as cathode materials; and NiO–CGO composite and chromium–manganite as anodes. The chemical compatibility and electrochemical performance of these electrodes with La9.8Ge5.5Al0.5O26.45 have been studied by X-ray powder diffraction (XRPD) and impedance spectroscopy. The XRPD analysis did not reveal appreciable bulk reactivity with the formation of reaction products between the germanate electrolyte and these electrodes up to 1,200 °C. However, a significant cation interdiffusion was observed by energy dispersive spectroscopy (EDS) at the electrode/electrolyte interface, which leads to a significant decrease of the performance of these electrodes.