Prenatal and perinatal risk factors, such as low birth weight, have been linked to higher levels of aggressive and destructive behaviours during childhood. Although low birth weight is associated with childhood externalizing behaviour, the mechanisms underlying this relationship remain open to empirical investigation. The current study extends the current literature by examining whether verbal skills mediate the relationship between low birth weight and childhood externalizing behaviour. A longitudinal analysis of data from the Fragile Families and Child Well-being Study reveals that verbal skills appear to mediate the influence of low birth weight on serious aggression and destructive behaviour at age 5. The implications of this research are discussed. Copyright © 2012 John Wiley & Sons, Ltd.