In important part of the work of Julio Corta ́zar the presence of a thematic axis can be appreciated that is reiterated: the attempts that the children make to emancipate themselves of the family nucleus. Besides to emphasize the fact that this aspect barely has been noticed and studied by the critic, the article shows the way in which, inexorably, the cortazarianos children fail resoundingly in their attempts to reach this emancipation. For it, the detailed analysis is offered of some of stories more known Corta ́zar, indicating and commenting other works of the argentine writer in whom the same situation is observed.