In this article the authors report insights into autism developed through their extensive experience of psychoanalytic therapy with children with autism. The first stages of body psychic development are seriously disrupted by this pathology, resulting in primitive anxieties of falling and of being liquefied. These anxieties are connected to the fragile development of body ego and of its related spatiotemporal organisation. The changes in children observed by the authors during the therapeutic process lead them to offer a psychodynamic assessment tool, which revolves principally around the development of body ego. After the initial state of 'severe autism', the authors describe three stages: the stage of 'recovery of the skin' (Bick); the established 'symbiotic phase', subdivided into 'vertical then horizontal splitting of the body ego'; and finally the stage of 'individuation'. First, the authors describe the principal psychoanalytic approaches to autism and reflect on the links possible with non-psychoanalytic work.