This paper explores the idea of possible proto-experiences of the prenatal child in the context of Bion's model of container/contained. The physical configuration of the embryo/foetus contained in the maternal uterus represents the starting point for an enquiry into the unborn child's possible experiences of its state of being contained in a container. The paper takes into consideration the sensory dimensions of auditory, tactile and kinaesthetic levels of awareness of the prenatal child in relation, respectively, to the maternal voice and the uterine environment. The author's hypothesis is that concrete prenatal experiences of containment may have their mental counterpart in the development of a proto-mental container and memory, the existence of which can be observed in the newborn infant. It is also suggested that prenatal proto-experiences of containment may prepare the child for further postnatal realisations of the pre-conception of containment and represent the experiential basis for the encounter with the breast. Observations of newborn babies in an obstetric ward, as well as the observation of a prematurely born child, seem to confirm the idea that the intrauterine experience of container/contained plays a role in the child's prenatal development. The meaning of prenatal thumb-sucking is explored in terms of the model of container/contained at a part-object level. An observation of the play of a three-year-old child offers material for further thought about the meaning and function of the introjected configuration of container/contained for the development of a sense of identity and symbolic thinking. The clinical case of an autistic child who survived a threatened miscarriage shows how the emotional containment in psychotherapy allowed the formerly inaccessible nameless dread to re-emerge and be represented and shared. (Contains 2 notes.)