Self-diffusion of Na+ and Cs+ ions in hydrous titanium oxide has been studied at four different temperatures, 25, 42, 50 and 57 degrees C. The conditions are set to favour the particle diffusion mechanism only, and the self-diffusion coefficients have been determined by using Paterson’s approximation. The activation energies, entropies and free energies of activation have been calculated and a tentative picture for alkali ion transport in titania is given.