The effect of a rainfall gradient, from a semiarid to extremely arid, on decomposition, were studied in the Judean desert, Israel. During the study period, the rainfall gradient obtained ranged from 308 mm to 24.4 mm. There was a annual mass loss of approximately 20% and 16% in the semi-arid and extremely arid regions, respectively. No significant correlation was found between the total rainfall and total mass losses. The data suggest that in an area where the conditions are not suitable for biological activity, the decomposition processes result from abiotic conditions, like temperature and radiation.