Boys admitted to a treatment facility do not always complete their treatment. This study analyzes the follow-up socialized coping of boys preponderantly classified as conduct disordered who were admitted to a residential treatment center. The boys were categorized into 10 different groups, only 1 of which consisted of those who actually completed treatment. The differences between groups and subsequent coping were fairly pronounced and highly significant. Further analysis indicated that very few of the group differences could be attributed to either age at admission or duration of treatment. Data analysis supported the hypothesis of treatment effectiveness in that boys who completed treatment did better in general than boys who did not, although those withdrawn by their parents did best of all. Furthermore, the rather pronounced differences among groups that failed to complete treatment raised certain methodological questions with regard to the practice of aggregating such groups in evaluation research.