This paper presents material from an infant observation in which the baby boy observed developed a number of psychosomatic symptoms and mannerisms in the context of particular difficulties in the mother-infant relationship. The paper focuses on certain features of this relationship, including the mother's ambivalence about breastfeeding and difficulties in her containing capacity. The baby was observed from a very early age to employ a number of precocious omnipotent defences. The links between maternal ambivalence and the baby's use of these omnipotent defences and his psychosomatic symptoms are explored, together with the impact of weaning. Some theory around the origin of psychosomatic symptoms is discussed.