Fifteen boys and 15 girls were asked to record for 2 days the time spent awake, eating meals or snacks, and sleeping. The salivary flow rates elicited by chewing foods were also determined. The mean flow rate (+/- SD) of unstimulated saliva was 0.26 +/- 0.16 ml/min and that of saliva while chewing six different foods was 3.6 +/- 0.8 ml/min. The mean times spent eating, and awake but not eating, were 80.8 +/- 27.3 and 820 +/- 59 min, respectively, and the volumes of saliva produced during those periods would average about 288 and 208 ml, respectively. If the flow rate is virtually zero during sleep, the estimated total salivary volume produced per day is calculated to be about 500 ml.