Few studies have examined the association between attachment and psychopathology in samples of clinically diagnosed children or the relation between attachment variables and the continuity of clinical symptoms. Clinic-referred preschool boys (n = 80) with early onset conduct problems (as indicated by diagnoses of Oppositional Defiant Disorder) were compared with a case-matched group of 80 nonproblem boys to determine whether observed attachment behaviors could: (a) differentiate the groups, (b) explain concurrent variation in problem severity within the clinic group, and (c) predict the outcomes of clinic boys 1 and 2 years later. Over half of the clinic boys with early onset conduct problems (54%) exhibited an insecure attachment strategy during reunion, as opposed to 18% of comparison group boys. All insecure patterns were overrepresented in the clinic group. Clinic boys were more likely than comparison boys to engage in provocative behavior when separated from their mothers. Contrary to our hypothesis, attachment variables showed little ability to explain concurrent or future variation in the problem severity or diagnostic status of clinic boys. We conclude that observable attachment behaviors exhibited during the preschool years are related to the initial identification of early onset conduct problems but may have little value by themselves in predicting the subsequent course and severity of problems in the 2 years following clinic referral.