This study examined the relation between family functioning and classroom problem behavior of children with emotional and behavioral disorders receiving special educational support. To this end, the Teachers’ Report Form and the Family Questionnaire were completed for 84 children (M age of 9.8 years) 2 times with a time lag of 11 months. Cross-lagged path analyses showed that internalizing and externalizing problem behavior in the classroom were stable over time, just as poor family functioning. Continuity of (a) poor communication, (b) discordant partner relationship, and (c) lack of social support were strongly associated with future total problem behavior in the classroom. Furthermore, parental responsiveness to a child’s needs was associated with lower future total problem behavior. A direct association was also found between externalizing behavior in the classroom and future poor family functioning. Implications of these findings for future research and practice are discussed.