Saliva from normally menstruating, pregnant and post-menopausal women was collected by catheterizing the excretory duct of the submandibular gland. The saliva was studied for rate of secretion, water content and the crystallization pattern. In addition the spontaneous secretion of saliva as well as the secretion stimulated by histamine and by pilocarpine were studied. The observations can be summarized as follows: Histamine had no effect on the rate of secretion, while pilocarpine increased the secretion considerably. In fertile women, the rate of spontaneous and histamine-stimulated secretion was somewhat higher during the secretion phase of the menstrual cycle than during the proliferation phase. No significant difference was found between the water content of the saliva in the two phases. In pregnant women there was a decrease in the rate of secretion as compared with normally menstruating women. In the post-menopausal women the decrease in secretion of saliva was still more marked. In pregnant women the crystallization pattern of the saliva was coarser than in menstruating women. After the menopause the crystallization pattern was still coarser and in one case no crystallization occurred at all. No constant differences were observed between the patterns during the proliferation and secretion phases, respectively.