The chloride level of the saliva of a group of 431 children was investigated and established. The mean salivary chloride value of this group of children was found to be 16.25 + 4.63 meq/1. Sex difference was not found to play an apparent part in the chloride level of the saliva. Ingestion of NaCl was found to have no appreciable effect, but stimulation markedly affected the chloride content of the saliva. Replic-ability of the chloride level in the saliva existed in 79-95% of 109 children tested at 6-month-intervals.