Young child's anorexia (0-4 years) may have organic or psychological origin, when parents-child relationships are concerned. The most complex and earliest forms often have unspecified aetiology. Psychopathological classifications, which emphasize the mother-child relationships, are essential reference marks. But there is now a consensus in the definitions: the diagnosis of infantile anorexia requires criteria of acute or chronic malnutrition. We mainly distinguish anorexia by early disorder of homeostasis, anorexia resulting from serious disorder of attachment, anorexia by disorder of mother-child interactions, and finally early and complex anorexia, mixing an organic vulnerability and a bonding trouble, which can be secondary. Treatments differ according to the selected aetiology. Even if the origin is not mainly the fact of a relational mother-child dysfunction, parents-child's relations require a support to avoid aggravation by interactive vicious circles (force feeding). More than other diseases of early childhood, feeding disorders require a good knowledge of the working hypotheses both in the field of the paediatrics and the child psychiatry.