Attachment theory provides an interesting background for thinking about externalizing behavior (EB) in early childhood and for understanding how parenting influences the child's outcomes. The study examined how attachment and parenting could be combined to explain preschoolers' EB. Data were collected from 117 preschoolers aged from 4 to 6 clinically referred for EB and their parents from a middle-high income population. Child attachment was measured with the "Attachment Q-set"; parent's remembered attachment in the family of origin with the "CaMir". Child attachment played a crucial role in mediating the link between parent attachment and EB as well as the link between parenting and EB. Paternal attachment displayed a direct and an indirect effect through controlling parenting and child attachment on child EB. Maternal attachment was a distal predictor associated with EB through child attachment, and independent of controlling parenting. These results are discussed with their applied and scientific implications. (Contains 5 figures and 1 table.)