Perovskite solid solutions with formula SrYb0.05(Ce1-xZrx)(0.95)O-3-alpha (x = 0, 0.25, 0.5, 0.75 and 1) were prepared. Their electrical behaviour was investigated using impedance spectroscopy between 200 and 1000 degrees C in different atmospheres, with and without hydrogen. Conductivities and their activation energies were obtained. The perovskites showed a high mechanical stability and a considerable high proton conductivity. Yb doped SrCe0.75Zr0.25O3-alpha seems to be a suitable electrolyte for solid oxide fuel cells.