This review covers basic principles of attachment research and its relationship to and implications for psychiatric and psychosomatic disorders. A great number of studies deal with the importance of attachment theory in the development of these disorders associated with distinct attachment styles. The most well-known concept is the attachment theory created by John Bowlby (1907-1990), which has strengthened our knowledge on early mother-infant relationships and influenced guidelines for child care. Within this concept, family structure is of great importance for the psychological development of the child and later the adult. Attachment research indicates that disturbances of patients with psychosomatic, e.g., somatoform disorders, in establishing relations must be seen in a developmental genetic context. A model of vulnerability is introduced which describes the development of psychopathology concerning the formation of representations taking advantage of attachment theory. Additionally, recent progress in cognitive neurosciences addresses attachment theory. During the last decade, neurobiological studies in rodents, primates, and humans indicate that early influences of psychosocial factors could have permanent consequences for brain structure and function. Besides the psychoanalytical and behavioral view concerning psychiatric and especially psychosomatic disorders, the integration of neurobiological findings will be a major challenge for the generation of further concepts.