The behavior and intraluminal esophageal pH of 48 infants (5-26 weeks old) were continuously recorded during the 120-min period following their ingestion of a standard volume of apple juice (pH approximately 4). To evaluate the effect of three basic behavior states on the frequency of infant gastroesophageal reflux, the data from all 19 of these infants who spent time in all three behavior states during the 120-min study were analyzed for this study. Results were expressed as the frequency of gastroesophageal reflux episodes per hour of time spent crying, per hour of time awake without crying, and per hour of time asleep. Reflux frequency while crying was compared to reflux frequency while awake without crying; reflux frequency awake (both crying and not crying combined) was compared to reflux frequency asleep. The results indicate that, as has been shown previously, sleeping decreases reflux frequency [nine (1-48) episodes per hour awake vs. two (0-134) episodes per hour asleep, expressed as median (range), p = 0.025], but that, contrary to expectation, crying appears to decrease rather than increase both reflux frequency [11 (0-84) episodes per hour crying vs. 17 (0-213) episodes per hour awake without crying, p = 0.035] and total duration [21% (0-79) of crying time with pH less than 4 vs. 41% (0-93) of noncrying awake time with pH less than 4, p = 0.025]. Crying does not exacerbate reflux in infants with gastroesophageal reflux disease.