Duplicate determinations of secretion rate and buffer effect of resting and stimulated whole saliva were made in 629 adults (286 males and 343 females) within an interval of 1-2 weeks. The subjects were arbitrarily classified into four separate age-groups. For all variables studied, a highly significant correlation was obtained between the duplicate tests. The secretion rate of resting as well as stimulated saliva was significantly lower for females than for males. For females, the resting secretion rate was negatively correlated with age. The buffer effect was also significantly lower in the females for both resting and stimulated saliva. For the females, the buffer effect was positively correlated with age and therefore, with advancing age, the females tended to catch up with the males. Irrespective of sex, the secretion rate of resting saliva was highly correlated to that of stimulated saliva. This relationship was established also for the buffer effect. However, between secretion rate and buffer effect a correlation was observed only for stimulated saliva.