Ceramic specimens of BaO . Pr2O3. 4TiO(2) (Ba4.5Pr9Ti18O54) were prepared by the mixed oxide-route. The single phase products were examined by High Resolution Transmission Electron Microscopy (HRTEM). Orthorhombic symmetry, with cell parameters a similar to 22.2 Angstrom, b similar to 12.2 Angstrom and c similar to7.6 Angstrom, was confirmed. On the basis of space group pnam (No. 62) and the crystal structural data of Rawn et al., good agreement was obtained between the experimental HRTEM images and images simulated by the multislice method.