A retrospective study of 86 children aged 6-12 years who had been hospitalized for psychiatric reasons revealed that adult criteria for borderline personality disorder could identify a group of children with many of the features attributed in the literature to the borderline child. The relative paucity of significant differences between the children identified as borderline and those identified as nonborderline raises questions about the validity and utility of the term. Further work is necessary to clarify the meaning of a vulnerability to psychotic regression in the disturbed child and the relation of such a vulnerability to the adult borderline personality disorder.