The thesis of this article, is that the analytic group is a place for a reliving and re-enactment of sibling relations. Psychoanalytic and group analytic writings about the issue of siblings will be surveyed. Juliet Mitchell’s theory of ‘sibling trauma’ and how it is reflected in the group analytic group will be briefly presented. It will be argued that the group is a place in which ‘sibling trauma’ is re-enacted and can effectively be treated. My thesis will be supported with clinical examples.