The present paper reports the kinetic data on THO/H2O exchange between natural mesolite, its exchanged forms and surrounding water. The release of THO in water as a function of time, temperature and type of cationic forms was investigated. Self-diffusion coefficients and thermodynamic parameters of diffusion are evaluated. The results are compared with those of other zeolites and discussed from the point of view of using mesolite from the Tabas region, as a storage material for tritiated water.