Objective: To examine sex differences in correlates of disruptive behavior disorders (DBDs) in preadolescent children using indicators of a wide range of well-established risk factors for DBDs and outcomes 3 years after initial assessment. Method: Analyses were based on data for 5- to 10-year-olds (n = 5,913) from the British Child and Adolescent Mental Health Survey 1999, and a 3-year follow-up of selected subsamples (n = 1,440) at ages 8 through 13 years. DSM-IV diagnoses were assigned using the Developmental and Well-Being Assessment at both contacts. Results: Boys and girls were equally exposed to most social and family risks for DBDs, with little evidence of differential sensitivity to these risks. Boys were exposed more to neurodevelopmental difficulties, attention-deficit/hyperactivity disorder, and peer problems and had lower rates of prosocial behaviors; together, these factors and physical punishment could account for 54% of the observed sex differences in DBDs. At follow-up, outcomes for girls and boys with DBDs were very similar. For children with subthreshold conduct problems at initial assessment, boys were more likely to go on to exhibit DBDs than were girls (25% versus 7%). Conclusions: Sex differences in the levels of a variety of child characteristics and interpersonal factors are likely to be important in understanding sex differences in risk for DBDs in preadolescent samples.