Non-nutritive sucking (NNS) activities were recorded in preterm infants born at gestational age 32 weeks or less during nasogastric feedings. Six infants on intermittent nasogastric feeding schedules were tested with a pacifier in their mouth for three 5-minute periods (before, during, and after gavage feeding). Analysis of the recordings revealed that NNS activities increased markedly during the intermittent nasogastric feeding schedule. The overall proportions of sucking engagement, the mean duration of sucking burst, the mean number of sucks per burst, and the mean duration of individual sucks within a burst increased markedly during gavage feeding compared with both pre-test and post-test periods. NNS by a group of five infants on continuous nasogastric feedings was similar to the pre-test and post-test of the infants on the intermittent nasogastric feeding schedule. These results indicate that in the context of intermittent nasogastric feedings, NNS engagement in tube-fed infants depends on stomach cues and/or temperature changes associated with tube feedings.