The standard BRE crystallization test using Dead Sea water (instead of hydrous sodium sulphate) has been applied on 10 limestone types. At the end of the 15th cycle, all the limestones have increased in weight. Most of the weight increase, being proportional to the porosity of limestone, occurred during the first five cycles. The 15 cycles of soaking and drying were not sufficient to cause any appreciable degradation of limestone. A longer period of exposure to the Dead Sea salts and factors other than merely soaking and drying may have been in effect in producing deterioration of tourist and industrial structures in the Dead Sea area. Effects of hydrous sodium sulphate and Dead Sea water on the studied limestones were found to be controlled by porosity. In low-porosity stones very little weight change has occurred, whereas, in high-porosity stones weight change was found to depend on the salt or salts used. This may be ascribed to the different behavior of single and mixed salts on one hand and the pore structure of the stone on the other.