This paper describes a long-term follow-up study in which the prevalence of emotional/behavioral problems in a group of 32 children and adolescents treated for leukemia is compared with both their siblings and a matched control group drawn from the general population. The performance of the groups at school and in social activities is also compared. Separate reports on the children were obtained from parents, teachers, and the children themselves using Child Behavior Checklist Lists (CBCLs). In general, there are now fewer differences between the leukemic group and the sibling and control groups than in a previous assessment; however, all of the informants consistently report that children treated for leukemia are still performing significantly worse at school than the matched control group. Possible causes for the continuing poor school performance of the children treated for leukemia are discussed.