We have carried out single crystal X-ray diffraction measurements of (Bi2O3)(0.75)(Gd2O3)(0.25) in the temperature range between 123 and 292 K. The structure was refined by the least-squares method, using about 70 reflections. The structure is very similar to that of delta-Bi2O3 and it was concluded that the oxygen ions are statistically located towards the cations ascribing to relatively short Gd-O bond distance. The decrease of the ionic conductivity is mainly due to the difference between electronegativities of Bi-O and Gd-O bonding.