The results of experiments in which iodine, dissolved as I- in LiF-BeF2 melts, was stripped as HI by sparging with HF-H2 mixtures have indicated that it may be possible to use such treatment to remove iodine from the molten fluoride mixtures used in molten salt reactor (MSR) fuels. This is of particular significance to MSR technology because it indirectly provides the means for removing a significant fraction of 135Xe, a decay daughter of 135I. Data obtained from transpiration experiments indicated a linear decrease of the logarithm of the iodine concentration of the melt with the number of moles of HF passed, and a linear increase of the reciprocal of the apparent equilibrium quotient Q'app = PHI/ (PHF [I-]) with the partial pressure of HF in the sparge gas. The iodine removal mechanism is explained by a model which assumes that the rate-controlling step is the transport of I- from the bulk of the melt to the surface and that the rates of the other steps are rapid. The removal of iodine from a molten salt breeder reactor (MSBR) fuel was analyzed in terms of the redox potential required to remove the iodine efficiently while preventing undesirable reactions in the fuel or between the fuel and its environment. The relative abundances of different iodine species present in the off-gas during sparging of an MSBR fuel were estimated; as expected, the results indicated a strong dependence on the temperature and hydrogen partial pressure. Low hydrogen pressures and low temperatures favor the formation of molecular iodine. High temperatures and low hydrogen pressures favor the formation of atomic iodine, while HI is formed at high temperatures and relatively higher hydrogen pressures.