Frustration in the feeding situation was studied in 7 full-term newborn infants during the 10-day period of their hospitalization after birth by measuring the latencies and amounts of crying, general bodily activity, and mouth activity upon withdrawal of the bottle after each 4th of the contents had been consumed. The amts. of these reactions decreased and their latencies increased as the hunger drive was reduced during the 4 successive stages of feeding. Although the general pattern of reactions was similar for all infants, individual differences in both quantity and quality of the reactions were shown. It was concluded that newborn human infants show decided frustration-reactions, the strength of the reaction varying with the strength of the instigation of the hunger drive.