The human infant's neurophysiological responses to feeding are poorly understood. We found recently a significant increase of EEG amplitude in the newborn during nutritive feeding, but not during pacifier sucking. In this study, we report EEG responses to feeding in 13 infants at the ages of 3 and 6 months. The undifferentiated response of the newborn was found to wane until the age of 3 months, whereas in 6-month-old infants, relatively abundant rhythmic 3–5 Hz theta activity was recorded during feeding with an amplitude maximum in right posterior areas. Cessation of feeding was followed by cessation of theta activity. The rhythmic 3–5 Hz theta response to feeding is likely to represent emotional arousal, as it is similar to previous findings showing posterior theta increase in other settings connected with emotional arousal in infants.