This review investigates the role of attachment security in the development of later externalizing behaviour problems. 33 studies were identified which have examined this relationship and these are discussed in terms of their key findings. The majority of these studies broadly support the idea that attachment insecurity and behaviour problems are linked. Differences in the findings across studies are discussed with consideration of the level of risk of the sample, gender of the children within the sample, type of measurement of behaviour problems, specific attachment classifications and the interaction of attachment with other variables. Future research investigating the nature of the interaction of attachment with other variables, particularly environmental risk, is suggested, as is further research into the mechanisms by which attachment influences future behaviour and the role of internal working models.