This study examines the relationship between disorganized attachment representations, defensive dysregulation in preschool children's doll play story narratives and child externalizing behaviour. Preschool children (n = 53) participated in the George and Solomon (1990, 1996, 2000) "Six-Year Attachment Doll Play Procedure" and their mothers completed a measure on child behaviour. Disorganized children's stories contained the most dysregulated content and their behaviour during the doll play interview was the most dysregulated. Ambivalent children exhibited the highest level of externalizing behaviour and dysregulated story content was only associated with externalizing behaviour for children classified as ambivalent. Implications for interventions and teacher--student relationships are discussed.