This study examined differences in social functioning, peer relations, internalizing behaviors, and externalizing behaviors between youths (ages 4–8) with sickle cell disease (SCD) and demographically matched healthy peers using parent-, teacher-, and youth-report versions of the Child Behavior Checklist and Missouri Peer Relations Inventory. Youths with SCD were reported by themselves to have more social and externalizing problems compared to healthy peers. Moreover, a significantly greater percentage of youths with SCD had borderline and clinical levels of social, internalizing, and externalizing problems relative to the healthy comparison group, Illness severity variables were not associated with any of the dependent measures. Overall, although the social functioning of youths with SCD is perceived by parents and teachers to be adequate, adolescents with SCD view themselves as having more.